deep penetrating nevus?

hi my daughter who is nine had a black spot removed and biopsy came back meltump severely atypical.they sent it to three different pathologist to look at because they were afraid its melanoma.the last pathologist said he believes it to be deep penetrating nevus.now they want to go back and take more tissue 5mm to do another biopsy.i ve been so sick over this because cancer runs in my family.both my mothers sisters died at age 45 and 48 one of pancreatic cancer and the other ovarian cancer.I just want her to get the right diagnosis before its to late for treatment.