Establish new routines w/ daughter

My very bright 10yo daughter is on the autism spectrum. The "routines" that she is used to come from a past of neglect and abuse. Her bedroom is her safe space that she rarely leaves. She either neglects or actively refuses to do things like bathe, brush her teeth, or exercise. And it is impossible to get her to go to bed at a reasonable hour, wake up, get ready for the day, or eat healthily. I'm a big believer in picking my battles and I want my daughter to feel safe in this house, so I'm reluctant to force any issue (except for medication compliance), but the pediatrician says that some of these issues are starting to affect her physical well-being. How can I establish new routines with a fearful, autistic preteen?