What disease is this?

I am a toddler teacher and have a one year old african american girl in my cl. She is bright, healthy, happy, and probably in the 95th percentile for her age category. A few weeks ago, with no warning, she was admitted to the hospital for brain bleeding. She survived with a blood transfuion and came back to cl with no incident. The child is now back in the hospital and no details about her condition are forthcoming so far, but the hospital hotlined her condition and I was contacted twice by a social worker asking questions about bruise like spots upon her body and had I noticed any signs of liver damage. The only indications, though fairly common in this age range, were loose stools and a few lethargic moments, all which were not good indications. She had a great appetite, slept well at school, and played like any normal toddler. Her reaction to either parent has never given us cause for concern, nor has her behavior been indicative of abuse. Could this be sickle cell anemia? Are her doctors proscribing a cause to symptoms that could be something other than abuse? I respect her doctors, but perhaps they are looking in the wrong direction, if not every direction. What else could this be? Sporatic cerebral hemorrage, bruise like areas on her arms, hips, stomach, no nausea, little lethargy, no inications of pain? Please help, I love all my students and especially this little one, who is so bright and special.