Obviously don't own any of the characters from the show.

AU where Brandon had a twin - Kasey. I love Stef's character and was curious to think about the kind of relationship she would have with a biological daughter - one that had inherited some of her traits and how she would cope with that. This story isn't going to be action packed -more about character development - but I just love imagining the different interactions this character would have with the existing ones. The story is fully written as it's a hobby of mine, but if people are interested I will continue to share this little universe until the end of the story (there are about 30 chapters but I may adapt if I get feedback that it is repetitive or slow). Hopefully any character development lovers like me will enjoy!

"Kasey! Now! Let's go! Move it!" Stef roared up the stairs to her eldest daughter. Kasey heard her mother calling but chose to ignore it. She had 10 minutes left to watch and didn't want to miss out on the conversations later in the day. It was playing with fire but she was pretty sure she could talk her Mom down from her frustrations. She had a gift for talking her way out of things. "Don't make me come up there!"

"Mom, I'll walk - just go!" It was so close to the end of the program. She could hear her siblings bustling out the door with her other Mom and a few words exchanged between them about how she was going to be late if she didn't get a move on. 5 minutes. She could hear the footsteps up the stairs.

"Enough - out. Now. You've already missed your ride and I'm not taking you in so you better run to be there on time!"

"Mom, literally 3 minutes. Can't I just watch in peace? I'll make it on time, really!".

"What is it you're even watching anyway?" Stef walked over to her daughter to catch a glimpse of the screen but Kasey swung around to obscure it. "OK - enough. Move, now - or the computer comes with me."

"Let me watch the last 2 minutes in peace and you can have it." Kasey zoned out as her Mom responded in disbelief that her daughter would be giving up her computer privileges for a few minutes of some unknown film or program. Stef walked over to her and Kasey swivelled her chair away across the room in what could have been a choreographed dance. One minute.

"Ho, ho, ho - you did not just do that!" Stef crossed her arms. 3...2...1... and Kasey slammed the computer shut.

"All yours." Kasey smiled that cheeky smile that had made her Mother's heart melt. Stef had had to train herself to overcome its powers - and more often than not failed. She wasn't falling for it this time though. It was too early for teenage smartassery.

"After that performance, that's mine for tonight. I hope you know that. You realise you're late for school now too - none of these things working in your favour young lady."

Kasey was used to a little trouble here and there. She never got into anything too deep - her and her twin Brandon were easily the most level-headed of all of the Fosters (except for their newest arrivals) but she was still her mother's daughter and had inherited the sparkle in her eye and her keen ability to speak in quips before she fully thought it through. "So just so we're clear, I'm already in trouble today, right?"

Stef's eyes widened and then her brow furrowed slightly. "Yes..." she responded nervously.

"So it'd be a pretty good time to ask you to sign something from school then?" There was that smile again to try and distract her Mom from the severity of the piece of paper she was handing her.

Stef glanced down at the paper as she took it. "You got a 35 in your history test?!" Her face was not impressed. Kasey's confidence humbled slightly as she saw the disappointment in her Mom's eyes.

"Mom, it was one test. It's really not a big deal - I just didn't quite prepare enough. You know me."

"Yes. I do know you - and you score 60 in the tests you don't prepare enough in. You're one of those annoying brainiacs who absorbs knowledge even when you're not trying - provided you've been going to the classes that is. Which makes me wonder..."

"Oh come on Mom! You know me."

"Yes. Yes I do." Kasey could tell that Stef didn't mean this in a positive way. Giving her daughter another glare she scribbled her name at the bottom of the page.

"You can have your computer back at the weekend." Kasey rolled her eyes.

"Mom, come on. You can't honestly be worried about this. It's one test - Jesus gets these scores weekly and you don't freak out about that. It's hard to maintain perfection." She was in battle plan of adorable arrogance. Stef wasn't falling for it.

"You're late for school." She said blankly as she swatted Kasey with the test before handing it back and turning her daughter towards the door. She kissed her on the cheek and swatted her again, this time slightly harder on the back. Kasey grabbed her backpack and set off before Stef pulled her back by her strap. "And no more of these, got it? You've worked hard, don't blow it now." She whispered comfortingly but with a hint of menace.

Kasey looked quite stern for a moment. "You know I did read an article the other day on that." Her Mom looked at her quizzically. "Youth unemployment has increased by over a third with a direct correlation to results of history tests in junior year." Stef couldn't help but smile. Her eyes narrowed as she said "Did I say the weekend? I meant Monday. Now go. Work hard."

She walked past her daughter briskly. Seeing one last opportunity Kasey followed her Mom down the stairs asking behind her. "But wait, how can I work hard if I don't have a computer?" Stef didn't break her stride. "Not my problem. You can use the doghouse one."

"But that one's got no internet - and most history is based on internet research..."

"Well fine, I'll just strip off all the fun stuff on yours. Email and Facetwit or whatever".

Kasey smiled as her Mom opened the door and signalled for her daughter to leave. "Riiight. You are going to strip down my computer."

"No I'd make you do it with me watching over your shoulder - like the way dads used to make their kids dig their own graves to scare them in the 70s." Stef rambled diverting into their mother daughter banter. "The 70s - did you have stone tools in the 70s...?"

Stef raised her hand to silence her daughter "Ah, ah, ah! Don't go there - you're in far too much trouble already and really are LATE FOR SCHOOL."

"Only got your genes to blame, Mom. " Kasey chuckled.

"That's what scares me. Go." She shoved her daughter playfully out the door and closed it before she could respond. Stef shook her head and laughed partly with desperation through a sigh. When your parents threaten you with "one day you'll have a daughter of your own and see what a handful you were" you don't ever really expect it to be so true. Stef was seeing a mini-her develop right before her eyes which she loved but also knew the capacity for trouble that could bring, along with the realisation she now had no choice to be victim to the witty retorts she'd spent a lifetime producing.