What Causes Three Vaginal Holes?

I could ask any body but there's no real Answer! I a 29 year old Mother with a Female doater who has asked about sex many times at the age of 9. She ponted out to me that she has funny looking holes? I told her that that was her Vagnal opaning but like her I don't understand why she has a funny looking Hymen. Looking like a ( Y) shape she has an upper opaning and two lower by the bottom. Funny thing is I look up all the types and shapes but can't fined one one this. Becuse this is skin like tisw were the ( Y ) is! Making the 3 holes!