Newbie question, I have a story inspired by a very local news item and think it could be worked up to a Lit.com tale. A female character with celebral palsy is abused, not violently, but sexually.
Allowed???
Abuse is abuse, and with a disability involved you could wander into rape territory fairly quickly. The question of adult consent arises, especially if the perpetrator of the abuse is able bodied and the victim is not only physically impaired but may also suffer intellectual impairment (which may or may not be the case). I can point you towards some comments from a PWD that you would be well advised to take on board, in this regard.
But you don't articulate the potential story line, so we don't know if you propose an affirmative story about the recovery of an abuse victim (which might have an appeal to the PWD community).
Or whether you find some erotic interest in describing the abuse of a person with a disability (which might not appeal very much at all).
Who would you be writing for? Whose point of view? Where is the erotic interest?
If you're going to describe the sexual assault and she doesn't end up enjoying it, then no it won't be allowed. The assaulted person must enjoy the assault.
If you never describe the sex and only the consequences to the person who assaulted her, then yes you can write it that way.