Should I continue this arrangement?

I had an oppertunity come up where I’d be cleaning this lady’s house. She’s on dialysis and her husband spends all his time taking care of her. It job is basically over, but I spit polish once a month. she forgets and thinks it’s once a week. I also mow the lawn every month. I do get compensated for my time, but I can’t make the drive like I used to and I’m thinking that I should stop doing it.

On one hand, it’s good karma and it’s a commitment I made. On the other hand, it’s not as beneficial to me as it is to her anymore. How should I handle this?