I feel gross just thinking about it but I'm starting to think she has a thing for rape/sexual abuse that she won't admit to outright (but which she's also too socially awkward to completely hide, hence all her weird commentary on ptsd). I've seen women who were kind of frumpy and unattractive like her talk about how they think sexual assault would be a desirable or validating experience because, to them, it would indicate that they're "attractive enough" to be assaulted by someone. So I assume Stephanie wants to believe she's so attractive that even ghosts want to sexually assault her (i.e., she likely fantasizes about getting raped by dead celebrities and serial killers).
The thing about her dad is a particularly nasty manifestation of that, I'd say.