Task: Question Answering
Input (English): My mum had another heart attack on Saturday afternoon . We thought that she would be out by today , that they were only keeping her in overnight for observation . My sister picked me up from a station and we went from there to her and mum's house , where we watched an increasingly distressing girly movie after she changed out of the half dress that she was wearing from the night before . While there , I managed to pick up all but the last of the stuff that I still had in the garage there from the old house . Amongst it , I found a mini treasure trove of Moana keepsakes , much of which I don't even remember being given . 
Question: What may have been the hospital's reason for keeping your mum overnight ?
Output (English): They wanted to verify her condition .