She may have been financially pressured into signing an NDA at the time. California recently changed the law so NDAs can no longer be used to keep victims of sexual abuse from reporting the crimes.

I haven’t read that it applies here, but it is a possible explanation. Fresh out of college, student loans and fear of being blackballed in an industry that is very reputation-based, “shut up and take this money or never work again”. If this is what happened here, waiting a decade and coming forward after the law changed makes a lot of sense to me.