I certainly can understand how frustrating it is for you and your mom. My mom has been in a nursing home for a little more than six months. She doesn't realize what is actully happening to her, but I think she knows something is not quite right.
Lately when I visit, she's been extremely down and expresses her worries....about what school to send the kids to etc.; (her kids are in their 50's) so you can understand that her mind is living in the past.
Yesterday I brought over a photo album of mainly pictures of me and my husband and our firstborn son. The pictures are 26 years old now, but mom took delight in seeing them and was saying what a cute baby he is...like they were recent pictures.
I've found if I can distract her somehow and get her mind off of herself, she seems to settle down and not be so wrapped up in worries. Unfortunately, mom takes no part in any of the activities offered in the facility. She becomes terribly agitated when I've tried to include her on something as simple as doing some crafts like acrylic paints, or anything that promotes some socialization.
Her days are spent sitting in a chair with an alarm pad by the nurses station. She's not allowed to walk w/o assistance now.
How I wish I had the answer for you. Maybe, like I said; if you can get her interested in something to take her mind of of herself, even if it's a few minutes a day, it might help.
Best of luck.