My Dad died last year. Before he passed I went to a Hallmark store and found a book for recording memories. Each page gave us topics to discuss and write his memories. We also went through old pictures and he told us many memories that were sparked by the photos. Doing this gave him a chance to relive some happy times and we recorded some great family history.
Or you could just buy a tape recorder or a diary for her and leave it by her chair or bed.
Best wishes to you and God Bless