Judge William Adams Beating Teen With Cerebral Palsy Sparks Outrage

what confuses me is "why now?" she could've just put it up when it happened instead of bear with it for 7 years

Fear? I don't know. Fear that some insane father figure was going to rape her or something even more extreme if she ever did something like that while she was still under his roof. On the offchance that CPS didn't take her to safety immediately, he probably would have, too.
Also, she has a disability, so she probably also had a "nobody would want to help me anyway" complex about it in her teens, that's normal under circumstances like those. Hell, it would be normal for someone without a disability if both parents were that mentally and physically abusive.