It is absolutely up to you how you spend your time. I don’t think that what your DIL, or your husband, or anyone else is doing is relevant - this is your decision and you are under no obligation.
However - my own mum never (or very seldom) looked after my children, and as a result they are not close now, which is different from her relationship with my sister’s children, whom she saw regularly. I know that she regrets it now, but they are adults with their own lives, and don’t have the memories or ties to my mum that would make them close.
I can’t help thinking that you have a choice here, and only you can make it. What I would suggest, however, is that you discuss this with your son, and decide between you whether there is a time in the week (not necessarily on Saturdays) that is convenient to both of you.
How to Keep Living at Home Longer
