Calling child and youth services?

I am a special education teacher. My students have severe disabilities and are non verbal. To keep this story short I have a student who has been being neglected for quite some time now (not bathed- put in diapers even though she is Toilet trained) basically being ignored in the home. Today the child came in and was dirty again- I sent her to my nurse and the nurse discovered an anal tear that was a half inch long ( child is small and 9 years old). We have worked with her for four years now and for some reason she wouldn't let my nurse touch or help her get clean. She has never done this. As a mandated reporter i reported the neglect and the tear. My question is- when we told mom we asked her to please provide us with a note from the dr to let us know how to treat the wound. Mom called back five minutes later and said the dr doesn't want to see her and told me we could just put Vaseline on it??? She is claiming it is probably just from a hard poop- but she didn't even see it? Why does that not sound right? What do you all think? Would a dr say that? Also....three years ago when her sister was her age the guidance counselor reported the same kind of injury because the father came in screaming that a girl in the school molested his daughter. The little girl was found innocent and no answers were given- I didn't know that until after I reported t but I'm sick to my stomach right now....