Did your daughter have an accident at school? It seems like that might be what she was trying to say? You can call the school and ask them what happened. If a child is injured they are supposed to file an accident report and give a copy to the parents.

Recently I got my daughter a book ("The Body Scoop for Girls") written by an OB-Gyn, just for girls, and it has a section on genital injury. There are a number of ways to sustain genital injury, such as "straddle injuries" where a hard bump or impact to between the legs occurs (playing on the bars at school?). There are also ways to get cut or bruised. These injuries can occur and not be related to sexual contact. The book advises placing a towel between the legs and applying gentle pressure until the bleeding stops. Then ice the injury. If the bleeding does not stop or there is some other indication such as really severe pain, a trip to the ER is in order. Here is the book's recommendations about when to call the doctor for a genital injury:

"1) If the injury is bleeding at all. For heavy bleeding, call 911.
2) If you can't urinate within a few hours of the accident.
3) If you feel OK, but the accident seemed scary and dangerous--a fall from a 12 foot high jungle gym, a collision on a bike at high speed, or anything that seems like it could cause a serious injury."

I think you should call your daughter and get more information on how she was injured at school. Ask her if she is still bleeding and how painful it is. It sounds like she might need to be with Mom right now instead of Dad, as she might be more comfortable having Mom look at her injury to assess how serious it is. Talk to her father too and explain that these injuries can be very serious and ask him what he has done to assess the injury, if she is still bleeding, has he applied ice, how often she is urinating, etc. This may be outside his capacity to help, so offer that you will come and take care of your daughter. He could either drive her to your place or you could take a taxi or rent a car for a day or have a friend take you.

I think you will learn a lot from a conversation with your daughter. If she won't give plausible details on how the injury occurred, then I think suspecting something sexual may be right on target.