/vt/ - Virtual Youtubers

Been putting this off for a couple days out of sheer embarrassment, but I've been struggling and figured I may as well come here to ask.
I've been plotting this sort of fanfic involving Mio, going from like girl next door to motherly wife material (nothing hardcore), and this is going to sound super autistic, but I feel like I'm struggling to make her character feel real. Yeah I want the character to feel grounded even in fanfiction, stupid I know lmao. It's just I don't know how to go about writing a believable story with her that isn't just "She's nice, kind, motherly, etc."
Do I just watch more of her streams to get a better grasp of her character (just started watching her over a week ago)? Or is there a trick to this?
Thanks