Could be hemrroids, not uncommon among children. But, I have read that any rectal bleeding should be sought out by a phsycian! I feel she should have already been seen also. This can be a warning sign for serious ilnesses(cancer!!) Probably just hemroids though. Kids tend to hold it to long and this makes them strain when they actually go. Especially if she is scared to go now because of the blood, she may wait even longer.
I think she should of already seen a pediatritian by now, pls take her in immediately. Bleeding out the rectum could be very serious.
I agree with learner. Please take her to a pediatrician immediately for dx. She could have pin worms. The way to check that is to take a flashlight when she is sleeping at night and look in her bed, you will actually see them. It's pretty common in children and comes from dirt under the nails and they often don't wash hands enough at that age. But definitely get her checked out.
Good luck.
She needs to see a doctor! Rectum bleeding always needs to be seen.