The first thing to say is can you learn to let go. Your own son is married, adults need to have their own independent thinking and ability, then the daughter-in-law is also his family members. You are an elder or a guest to their family! Why did you come to your son's house? Is it because you don't feel comfortable with your son's ability to do things? Or are you unsure of your son's ability to do things? Or are you worried about your daughter-in-law? If not, then why do you go to your son's house so often?
In fact, you should understand your son's daughter-in-law. People have just entered your home and don't know you very well, so of course they like to find a familiar person to help them. The best choice is your own mother, that is, your in-laws, this is no excuse ah. If you feel that she is badmouthing you behind your back, then is this something you heard or did your son overhear you? It's mainly your words that can be ignored. If you take it seriously, you will put your son in a dilemma, don't you think so?
You should still be grateful to your daughter-in-law. It's good that she's letting your in-laws help with the kids, too. You can have more time to do what you want to do, like traveling, learning a profession, even square dancing. Otherwise, you would only be able to take your grandchildren to the square, don't you think so? If you think of it this way, shouldn't you think that your daughter-in-law cares for you. I don't want you to be so tired, don't you think so?
A family together, should be mutually sympathetic, should be better to get along with each other, and not because of who who's a bad word in the heart, which is not conducive to the harmony of the family, but also not conducive to the son and daughter-in-law relationship.