Soaking in some warm Epsom salts or soapy water with a little Dial soap for about 10-15 minutes would help to soften the crust. The longer the better. Taking a wash rag and rubbing it some after softening may get some of it off. You have to rub a bit, and it can bleed a little, but that is a sign of good healthy tissue, so it is okay. She has a really dried out prolapse, and hopefully, you can get that off. Then coat it with some ointment.