Okay any bleeding per vagina in a child so young is abnormal. She needs to be seen as a matter of priority by a caring doctor. Yes, a uti can cause bleeding but it is usually red blood. It sounds like that's not the case. If it were me I would be collecting her from school - take her for a milkshake & investigate caringly and gently.

Yes, this is a red flag to abuse - & that's not something any Mama wants to hear. Children are not always abused by adults - children too. She could have injured herself another way... She could be beginning menses. If she is she still needs to be seen by a doctor. This is premature menstruation if she is menstruating and a paediatrician will need to be involved.

I am sorry if I sound direct. Some things need direct. Any pv bleeding in a young child is not to be overlooked. I know you are not overlooking it - just reassuring you that acting quickly is the right thing to do in this situation. Big cuddles darling this is a big one for you to deal with.