Is Karen possibly a bit OOC? Yes. Do I care? No. The fic is being written with the idea to have Karen and Grace become a thing in later seasons, just to give a heads up on that now.

I have tried my best to use American phrases when writing speech, but I am not American, so I may have missed some

The crowd around them had thinned out a bit, the other people in the bar finally growing bored of Grace being in a wedding dress.
"Help me get this thing off my head, Will. It's annoying me," Grace whined, gesturing at the veil attached to her hair. Will obliged, careful not to pull too much hair as he removed the veil. Grace snatched the offending article out of his hand, using it to mop up some beer that she had just spilled on the bar.

"Grace, don't do that."
"Why not? It's just a piece of material, I'm not going to wear it again. Even if I do have a chance to get married again, I'll buy a new dress. Getting married in the dress you wore to your last wedding feels like it'd be a bad omen to start your wedding on. And it's not like it's a nice dress, I can definitely find something much nicer than this."
"I'm not going to argue with that, even with five minutes you could have found something better." Grace punched him in the shoulder as he finished speaking, and he winced, making a mental note not to annoy her again when she was drunk. He'd thought her sober punches were painful.

They sat in silence for a few minutes, sipping their beers, before Will spoke again.
"You are going to get married, Gracie, and to someone much more deserving than Danny. You're a great catch: you're kind, you're funny, you're beautiful, you run your own business. Any man would be lucky to have you." Grace smiled, resting her head against his shoulder.
"I know. I also know that I'm not going to be marrying any man that you don't think is enough for me. Though, in future, it'd be great if you could tell me something major like that much earlier into the relationship. Waiting until we've reached proposal point was not your best move."
"You're right, and I'm sorry. I should have told you much earlier how I felt about Danny."
"And I shouldn't have been so cross with you for looking out for me." Will smiled, turning his head to drop a kiss on her cheek. He signalled to the bartender for another two beers, and then frowned slightly as a thought occurred to him.

"Grace, why did you forgive me?" Grace straightened up, staring at Will with a confused look on her face.
"Were you not listening to me? I just told you, I forgave you because you were just looking out for me. If you're not going to listen, then I'm going to go home." She started to get up, but Will stopped her.
"No, no, I got that. I meant, why did you forgive me so quickly? I'm glad you did, but you were at my office apologising about a half hour after I had left yours. After something so big as ruining your wedding, I would have thought it'd have taken you at least a day to forgive me, not less than an hour."

The bartender placed two beers on the bar in front of them. Grace grabbed one and took a large swig before turning to look at Will.
"I want to say it's because I'm growing as a person, but I'm too drunk to lie. It was because of something Karen said." Will choked on the mouthful of beer he was swallowing.
"Karen?" he spluttered.
"Yeah, she said I'd been a bit harsh on you, and if Karen thinks something is harsh, then it's got to have been really awful. Although, it's nowhere near as bad as some of the things she's said." Grace frowned at her beer bottle, picking at the label as she puzzled something out. "You know, I don't think she really means half of the nasty things she says."

Will choked on another mouthful of beer, and gave Grace a look that was a mix of shock and bewilderment.
"Doesn't mean the things she says? Come on, you can't really mean that. She's an incredibly insensitive white woman who married the man with the largest wallet she could find, and she is constantly hopped up on drugs and alcohol. You should have heard the way she was talking to her maid on the phone, treating the poor woman like she was an idiot. Karen hasn't got a nice bone in her body, and she never does anything for you. I still don't understand why you haven't fired her yet."

"I've already been over this with you. She has more social contacts than anyone I have ever met, and these are rich people. Very rich people. They seem to constantly want their houses redesigned, and they're keeping my business afloat. The rest of my competition has to make a name for themselves before they can even begin to dream of designing for some of the clients that I have. With Karen as my assistant, I've already got the clients. Making a name for myself is an afterthought. And I'm pretty sure she does do things for me. On days when I've been really busy, or really stressed, and I've left the office in a state, she leaves after me. When I come back the next morning, papers have been filed and faxes have been sent that I'm almost positive I haven't done myself."

"Grace, there are a thousand people in this city who could do the exact same job for you, without the mean comments."
"She doesn't cash any of the checks I give her, no one else in the city would work for me for free." Will chuckled, raising his bottle in the air in a toast.
"That is something to keep her around for," he joked. Grace laughed in agreement, clinking her bottle against his, both then taking a swig from their own bottles.

"She is a good role model, you know, if you want to learn to be confident."
"Grace, confident is not the word that'd first come to mind if someone asked me to describe Karen."
"I know, but she is confident. Okay, so maybe she shouldn't be quite so unafraid to say what she thinks of people, but she doesn't take nonsense from anyone. That's part of the reason I hired her, not just because of her contact book, but because I wanted to learn how to be that confident. The final reason I hired her was because of a moment during the interview, when I'm sure I saw a softer side to her. She told me one of the reasons she wanted to work for me was because she'd wanted to be an interior designer when she was younger, and for just a second she looked so sad."
"Grace Adler, you are a sap."
"Maybe I am, but I can't help feeling that there's far more to Karen than we get to see."

Karen sighed as she lay back in her bed, placing the empty glace on her nightstand. She'd spent the last hour brushing up on her Spanish with Rosario, after the embarrassment of forgetting the word for toy store earlier that day. To make matters worse, Will had walked in at that exact moment, and she'd panicked briefly. People expected her to care nothing for her servants, and Will was no exception. Being fairly fluent in another language just so she could communicate with her staff properly was something she was absolutely not supposed to be, and she took great care to present herself to people in the exact way they expected her to be. Luckily, Rosie had come to the rescue, suggesting she just said the name of the shop, so Karen had done just that, putting a bit of an exaggerated pronunciation on it to make sure Will was annoyed on Rosario's behalf. It had worked, but she needn't have been so worried. Will had been too caught up in his problems with Grace to care.

Grace. Karen sighed again, shaking her head slightly. Danny had been perfect. He'd had money (nowhere near as much as Stan, but then not everyone could be as lucky as she had been), he'd been handsome enough, and he'd loved Grace. So Grace didn't think he was The One. Big deal. Karen didn't honestly think Stan was The One for her, but they got on well enough, and they were fond of each other. That was far more than some couples had. Okay, so commenting on limousine phones in response to Danny wanting to spend the rest of his life with her wasn't a good sign, but they could have got past it. But Grace believed in true love, in love that transcended boundaries and could never be defeated. Karen wasn't sure if that kind of love even existed.

She knew one thing though: Grace was going to be good for her. She was optimistic about things that Karen could only view in a pessimistic light, she cared less about what others thought of her (not much less, but still, Karen could learn from it), and she had followed her dreams. Karen hadn't been sure what kind of job she'd wanted when she had decided she needed to get out of the house and meet some real people, unlike the socialites she spent most of her time around. The moment she had seen the position as an assistant to an interior designer, she had known it was the job for her. She'd wanted to be a designer ever since she was small, but circumstances (and her mother) had conspired to make it that she never achieved that dream. Nowadays she had unlimited funds to decorate the mansion however she liked, but the challenge of decorating a house perfectly to fit someone else's taste was much more appealing. If she worked with Grace for long enough, maybe one day she'd be allowed to decorate a small part of someone else's house. More importantly, if she worked with Grace for long enough, maybe one day they'd be friends.