Delusions

I am new to this board. My stepdaughter is 28 yrs. old. The doctors at the hospital where she was admitted Wednesday morning believe she is bipolar and is having delusions. For some reason she is very upset with her father and believes that he molested her, but cannot provide any specifics or even a time when this may have happened. This is so sad and upsetting for her Dad and I. He has always been such a good father and so supportive of her through out her life. She has all the classics symptoms of bipolar disease. Can anyone tell us if delusions like this are common with this disorder? We are so fearful that she will continue to have these delusions and she is telling everyone she knows that he molested her. Why would she turn on those who love her the most? A couple of years ago she felt like she was having suppressed memories of being molested by her mother's boyfriend (when she was a child). She said her mother knew it happened but told her not to tell anyone. Could this incident be mixed up with what she now believes to be true about her father. Any info would be appreciated. We are new to this problem and just don't know where to turn.