(Disclaimer: These letters are not about ANYONE in my life in particular. I am just sharing my thoughts in general. I realize that some mother-in-laws and even mothers are extremely difficult, abusive, manipulative, and divisive. While I feel for you, I am NOT writing about those situations, but rather about regular, imperfect but well meaning MILs.)
Another disclaimer- I am not a mother-in-law, so if you are, please comment and let me know how close I came to how you feel. We daughters need to hear it.
We had a mother-in-law panel at MOPS this past year that was very eye opening. We got to ask them questions- why do they do what they do, what do they expect from us?, etc. What I heard there and what I've seen around me in other situations is a lot of hurting mother-in-laws.
Our generation is different from theirs, for sure. We have the internet with access to lots of research on health, parenting, etc. We don't have to rely as much on our own mothers and MILs for that wisdom. We are even discovering that they are/were wrong sometimes! No, baby cereal at 6 wks is not OK. Babies don't need to cry to exercise their lungs, etc... The other thing that's different is how independent we've become. We want to leave our parents, run away with our husbands, never to be bothered by family again. I'm here to tell you that this is wrong thinking.
Your MIL needs you, needs your children, and dare I say, maybe you and your children need her. The natural situation surrounding MIL & DILs is such that both parties can easily feel uncomfortable around and threatened by the other. DILs are new to the family, wondering how they'll fit in. Especially in this day in age, MILs have to wonder whether their new DIL will accept them or push them away. Both are wondering where the son's loyalty lies. (It should lie with his wife, by the way, which is why this is YOUR issue, to make things right with your MIL. A husband can almost find no safe way to bring this up to you if there is a problem.)
Your MIL does not want to control your life. She doesn't want her son back. She doesn't want to steal away your children and raise them how she sees fit. She most likely doesn't think you're a horrible mother and wife. That's probably your own insecurity rearing its ugly voice in your mind. She wants to be included and involved. She wants pictures and crafts the kids make and to be invited to special events like birthday parties. She wants you to listen sometimes to her advice. Take it or toss it, but at least listen. She wants you to tell her straight up if there's a problem with how she's doing things. (a REAL problem, NOT, "you put them to bed 30 minutes late, so they can never come stay with you again." or "Johnny can only eat 3 servings of fruit a day and you gave him 6.")
Using your children as manipulation pawns is not OK. They need their grandparents, and their grandparents need them. You are not an empty nester yet, but just TRY to put yourself in those shoes for 2 seconds. It is hard, and you just want family around you and to feel you are still useful in some way in influencing the younger generations for good. Try to imagine how it would feel to have your son (because his loyalty should lie with you, remember?) and grandchildren never come see you because your DIL is too busy, too strict, too whatever. Especially if you make lots of time for YOUR family- this can sting even worse. They don't have to do things exactly like you do to be good caretakers of your children.
I have just seen far too many DILs being overly critical of their MILs and being way too controlling with the relationship between her and her grandchildren. Expecting them to respect your wishes is one thing, but it can easily go overboard into being nit picky, all in the name of "boundaries". You feel you have something to prove, that you are a better mother than she, but it's just not necessary.
On the other side, I have seen DILs become patient and accepting even of a difficult MIL, and this turned the relationship around. Now they have a healthy relationship with mutual respect. Let your guard down; let go of some control; trust God with your kids; and be more selfless. Everybody will benefit.