Hi,
Welcome to the ehealthforum and I am really glad to help you out. The vagina and vulva are delicate, yet resilient structure made of skin, mucous membranes, muscle and so forth. The lining of the vagina is very similar to the tissue that lines the inside of your mouth. It's soft, squooshy, and it bleeds when it's cut or roughly rubbed.
This bleeding looks like trauma to the vagina rather than pregnancy which is less likely to occur after 4 days of periods. You should get it evaluated from a gynecologist as she may need medicines like tranexemic acid to stop her bleeding.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care.