*Trigger warning* What should I do about this situation with my daughter?

My daughter is almost three and made a comment that made me really uneasy a few days ago, and I tried to ask her about it, and she wouldn’t answer me about it, so I just let it go. I went to change her diaper, and she said, “my butt is pretty” I tried asking her who said that to her etc. and she didn’t answer so I let it go. Today she was at my mom’s house visiting while I’m at home and my mom called and said that she had diarrhea really bad and she went to change her, and she had it everywhere, and she wiped her, and she started screaming and crying, so she looked, and there’s a cut in/on her vagina (I have not seen it yet, but she’s bringing her home, and I’m going to look) What should I do? Do I call her dr or who do I call? There should not be a cut there at all, and I don’t know what I’m supposed to do to look further into this or what? Please help. I’m so concerned especially now that she has a cut there, and from the comment, she made as well. I just want to make sure she’s safe. She’s normally only with me, so I don’t want to assume something is happening, but I don’t want to just turn a blind eye either.