When this happened to my mother, who passed 7 months ago, I would offer to cook the meal at her house. I would compliment her in her life long skills and tell her I learned so much from her and wanted her to be able to share in the joy I felt having acquired her experience and knowledge. I had long since surpassed her culinarily, and the time spent together wasn’t about the food. I would ask her to please let me repay her for all those years in the kitchen and meals served up by her; to please let me have a turn. It worked beautifully. After the first meal she let me make, she would ask what I was going to make for dinner when I visited. Granted, I didn’t see her that often because of a variety of reasons, and we didn’t always get along, but this one thing ...the sharing of the cooking .... seemed to make her happy the latter portion of her life. If you don’t enjoy cooking and aren’t good at it, offer to bring take out or actually take her out to a nice restaurant. So many ways to work around this besides pointing out what she likely already knows and feels bad about.