Maybe you and your wife can come up with a system for how she agrees to do things for others. For instance, perhaps you can make an arrangement that when things come up during the day, your wife decides if she can do it, however, if it is something that needs to be done in the evening or during the time she is generally with the children, she can say, “I have to ask my husband if this will work for us and I will get back to you.” In this way, you can help your wife navigate the tricky situations and be her excuse if she has to decline. Obviously, there needs to be a balance and sometimes your wife may feel that she should agree to something even if it may be a little inconvenient for you and the family. In these cases, it will be important for you to hear your wife out and accept if she feels that her help for the community is really needed.
It is also prudent to help your wife understand why you feel the way you do. Explain to her that though your mother is wonderful and you love her, you sometimes felt that she was not there for you as a child. You can also explain that you do not want your children to feel the way you did and that is why you are worried at times. If your wife is cognizant of your feelings and your reasons behind them, it may empower her to put you and the family first. May you and your wife have much nachas from your family and enjoy your s’char for all the amazing chesed that she does.
Hatzlocha!