Is Marissa Cirillo sick? Like something life threatening? BONE MARROW?

My friend works at an Atlanta hospital,and said that Marissa Cirillo was in intensive care on Christmas,and that she had to get bone marrow. What's wrong with her? She also said that she had so many celebrity visitors, that they had to bring in extra security! But no parents? I feel so sorry for her. I heard she's had a horrible life.