A/N: As much as I love Grucy fluff, I'm almost equally interested in Lucy/children bonding time. I have a soft spot for Margo in particular because I feel like she would be the most effected by Lucy becoming a member of the family, much like in the first movie when she had the most dramatic experience out of the sisters learning to trust and eventually love Gru.

This story takes place shortly after Gru and Lucy are engaged, which in my timeline means just slightly more than a year after they met. This is a special little vignette that's been in the works for a while now, and to warn you, it's pretty angsty. I hope y'all approve of my interpretation of Margo's past and feelings, feel free to let me know what you think!

Mom

The girls and a few Minions were playing video games in the living room when Gru and Lucy came home one night. Margo was the only one just watching them play, so when the two adults entered the house, she turned her attention towards them and noticed something strange. There seemed to be some tension between them, which was highly unusual, even after particularly stressful missions.

"Hey guys." Margo said once they both reached the living room. Both Gru and Lucy seemed to realize at the same moment that they weren't the only people in the room, despite the noise from the video game. Not exactly looking at each other, they rather awkwardly greeted Margo before Gru simply walked over to her.

Approaching the couch where Margo was currently seated, Gru put his arm around her in a light gesture of a side hug. He glanced over at the other girls, noting that they were completely engrossed in their game. "How was your day?"

Margo pretended to ignore the fact that Gru was acting strangely distant. "Um, good, I guess. After we finished our homework, we started playing video games."

"Good. I'll be in the lab if anyone needs me."

Margo watched as Gru disappeared into the hallway. She looked up at Lucy, who had been idly standing by. "What's up with him?"

Lucy stepped closer and looked as if she was trying to think of a kid-friendly way to describe what was going on. "Your dad is just tired, and a little flustered. We had one heck of a mission today. Did you girls have dinner?"

Margo was more than suspicious now. First, Gru was acting strange, and now Lucy is changing the subject?

"Yeah, we ordered pizza. There's still some left in the fridge if you want some."

"Thanks, but I'm not too hungry. I think I'll turn in early, actually."

Lucy. Turning in early. On a weekend. Margo didn't believe her for a second. Lucy was usually the one that kept them up on the weekends because there was no regular bedtime for school. She'd play or watch movies with them while Gru either joined in or did work in the lab. Something was definitely up.

"Ok then." Margo shrugged. "See you later."

Lucy waved and turned to climb the stairs. Margo looked back to her sisters and the minions still playing, knowing that they were too distracted to notice the odd exchange that had just happened. The eldest of the three sisters couldn't help but worry just a smidge; it was a kind of worry she'd never felt before. She wondered if they'd gotten in a fight, a fight so bad that they weren't talking to each other. Her friends had told her about their parents' divorces and how fights between them were a daily occurrence, but Gru and Lucy weren't even married yet.

Despite the bad feeling she had, Margo refused to let her imagination wonder without a proper investigation.

…

About an hour later, Margo had gotten into her PJs and crossed the hall to Gru and Lucy's bedroom. The door was slightly open; a kind of code that Gru had made signaling that it was Ok to come in without knocking. Gru learned early on that with doorknobs that little girls couldn't reach, it was hard for them, Agnes in particular, to find him in the middle of the night when they needed something.

Poking her head in the door, Margo found Lucy in bed, reading. Lucy noticed right away, either because she was always so alert or because she wasn't too invested in what she was reading. Either way, she closed her book and beckoned Margo to come in.

"What can I do you for?" She asked, her usual pep more prominent in her voice then it had been just an hour before.

"I…wanted to ask you something." Margo said. "Did something happen on the mission today? Something that made you and Gru mad at each other?"

Lucy didn't answer right away, but was not surprised that Margo had noticed that something had gone on between her and Gru. She patted the bed just in front of her, suggesting Margo sit down, which she did.

"Can't pull one past you, huh?" Lucy said, trying to make a bit of a joke of it. She sighed and shrugged. "We had a fight, actually. It was our biggest yet. I don't want to get into any details, the whole mission being classified and all, but I can tell you that who we were supposed to be fighting…totally started it."

Margo gave a breath of laughter. "I can't imagine anyone being able to get you two mad at each other. You guys never fight."

"Sure we do. We disagree all the time, we bicker some days, it's totally natural, and we always get past it." Lucy reached over for Margo's shoulder, emphasizing the importance of her next words. "You have absolutely nothing to worry about. We've made it through worse than a silly little fight like this. Nothing keeps us at odds for long."

Margo smiled, happy that Lucy was sounding like herself again and reassuring her that everything was fine. She really loved having Lucy around. As much as she loved Gru, there were just some things she couldn't talk to him about, so it was nice to know that Lucy was there for her.

"Can I—can I tell you something?" Margo asked as she fidgeted with her glasses, a nervous habit, something on her mind that she'd wanted to say for a while now.

"Of course." The red head replied.

Margo took a moment to breathe. She definitely trusted Lucy, and she needed to get something off her chest. "I…I just really need you to know something and… I haven't even told Gru this."

With that, Lucy knew that this certain something the girl had to say was terribly personal. Turning her full attention to Margo, she tried for a split second to find something to say, but knew that words couldn't describe how much she wanted Margo to trust her. Instead, their eyes met and she nodded, ready for whatever Margo needed to tell her.

The girl took a deep breath before speaking. To Lucy, she looked as if she'd been holding onto a secret for far too long. "Edith and Agnes are too young to remember, but we had a mother once. I never talk to them about it because they don't remember, but I was six years old when we had to leave her. She couldn't take care of us, and looking back on it, I don't really think she wanted to."

Margo paused, trying to find the words to continue. Lucy took the opportunity to pull Margo into an embrace, and by Margo's reaction of hugging her back, she could tell that the girl was grateful for the comforting contact.

"It still hurts. I still don't know what to feel or what to do about it. But what I really wanted to say was…thank you. Edith and Agnes really look up to you, you're the closest thing to a mother they've ever had." Margo pulled away to look up at Lucy. "You're closest thing to a real mother I've ever had, too."

Lucy couldn't help but tear up. She was incredibly happy to have made this connection with such a special kid. Her mile was effortless as the two hugged again. She let a tear fall as she held her soon-to-be-daughter close. "You know, I never ever thought I'd be the mothering type. I was never good with kids."

Margo laughed. "Neither was Gru, at first."

…

Gru was in the lab looking over blueprints when he heard Lucy's footsteps echoing off the walls. He could tell it as her by the timing of her steps, even without the heels. She was the tallest in the house, therefore the timing was drastically different for her then anyone else.

He wasn't mad with her anymore, and if he was being terribly honest with himself, he wasn't even sure why they had started arguing in the first place. They'd caught the bad guy, gotten away scotch free, and were home by dinner. He supposed he'd gotten a little on edge and taken it out on Lucy, regrettably.

That villain had pushed the wrong buttons with him, talking at him about being a disgrace to the villain name. Gru had accepted the fact that he could no longer be a villain, but having people ridicule his decisions was something he did not tolerate. And then he snapped at Lucy, stupidly venting while she was just trying to get him to relax. He sometimes hated being as short tempered as he was, Lucy didn't deserve his wrath.

His thoughts were interrupted when he felt a slender hand tap his shoulder. He turned and saw that she didn't look mad either, her soft smile evidence of that.

"Hi." She said.

"Hey." He replied, a soft smile tugging on his lips for a moment. A silent few seconds passed between them before he spoke up. "I'm sorry."

"Me too." Lucy replied without hesitation.

She took a step further and wrapped her arms around his shoulders, he in turn wrapping his arms around her middle. They were like that for longer than usual until Gru pulled away enough to see her face. From their close proximity, he could see that her eyes were slightly red and that there was a tear strain on her cheek. He brought his hand to her face brushed her cheek with his thumb.

"Hmm?" Lucy inquired.

Gru looked into her eyes, concerned. "You were very upset with me?"

"Oh, no." She said, realization dawning on her. "Margo and I had a talk just now. She, um, confided a lot in me."

Gru became curious. Whatever it was that Margo had said, it seemed to make her very happy, evident by the wide smile on her face, but had also made her cry. "What did she say?"

"Oh, well, we talked about a lot of things." Lucy said. "And I'm pretty sure some of it is classified information."

Gru rolled his eyes, about to say something when Lucy suddenly hugged him tightly, almost too tightly. She got like this when she was excited about something.

"But she said that I was the closest thing to a mother they'd ever had!" Lucy let go of Gru and took his hands in hers, swinging them around. "I can't believe it!"

Gru took a minute for the statement to sink in, but was just as happy to hear it as she was. He swept her closer and planted a proper kiss on her lips, pulling away only to reaffirm her joy.

"Believe it.