We have three octogenarians we have to shop for. Like your mother they are all healthy and active.
Some things we have done....weather station. That one was a hit with all three. They liked being able to easily check the weather and time.
A digital photo frame. I filled SD cards with pics from all the family thanks to facebook.
The year before last year we did new pillows and sheets. Yes they all had plenty, but none of the ladies had updated those in quite a few years. I haven't heard a thing about the sheets, but the new pillows seemed to be appreciated.
I stole the idea from my SIL, but one year we did garden tours. We were able to find one in each city. They got to go with friends or family and have a nice breakfast. Then they spent the day touring fancy gardens around town.
For two of the three ladies, I think we are doing gardening classes this year (my grandmother has poor vision and can't do this). We are also toying with a gym membership, so my husband's grandmother can swim laps. She really enjoys swimming. For my grandmother I am making her a calendar. But I am using pictures of all of her children instead of current family pics. She keeps the pictures stored in boxes, so I thought it would be a nice way for her to enjoy them.
For mother's day last year, we got fancy self inking address stamps. And for my grandmother with poor vision I made her labels to address things to her family and friends. The stickers are printed in large print so she can easily read them.
HTH!