I think that the important thing is to keep in touch with your son and grandchildren. That is your major concern and so you have a limited sentence. If you keep your goal in mind, it doesnt matter what she thinks or how she sees herself as being in charge of the situation, You know that you just need to keep going until the children are old enough to have a relationship with you , which she doesnt rule. Therefore at the worst you may have to put up with her until they are 18, but probably by early teens , the children - who naturally tend to go against their parents at that age - will be pleased to both have a lovely relationship with you, whilst also really annoying her!! She will get a taste of her own medicine, as they have learnt from an expert!! Take whatever opportunity you can to have time with the children on their own, try to organise days out with them on their own with you. Perhaps you live near enough to offer to drive them to classes or whatever. You win on two levels, It would be seen by most people to be very nice of you to be a taxi service, saving her the job. She cant win that one, either you do it and get your private time with the grandchildren, or she snubs you and has to do all the driving herself, with the children resenting her and her friends (if she has any!) wondering why on earth she wouldnt want the free help and yet no doubt will moan about being a taxi service. She will get no sympathy so I would say that comes as Checkmate!!! Watch and see what interests and hobbies they get into, and of course encourage anything that means they spend time with you and not with her. Do you swim? Dont have to be a world class swimmer, but again a chance to mix in a very open place, so she cannot say you are luring them away, you get a little exercise, they get a chance to go to a different pool perhaps, and of course they will be ravenous when they g et out so you can have a simple meal with them. Dont go for anything extravagent or expensive. She will judge you by her own standards and think you are just using the occasion to cause problems.
Now another quite useful thing that I used to tell my students who were anxious about an exam , such as speaking a foreign language or going for the driving test. What you do is this. Before you go into the room, clench your fists, and your face, grit your teeth and clench your shoulders. As you go into the room, try taking a deep breath, drop your shoulders and relax your muscles. Look directly at the person and in you head imagine them sat on the loo with their pants round their ankles. It invariably brings a smile to your face. No one else knows what you are smiling at , so far they cant see inside your brain! So the horrible daughter in law is amazed that after her rude and ignorant behaviour, you behave like the queen with a smile on your face. The rest of your family and friends are amazed too , that you could behave like a saint with the woman from hell. You have said nothing yet. She cannot answer with a barbed reply when you havent said a word. You can also smile inside as you see how your plan is working. If she starts to be awkward you can nod or , more fun, let her ramble on in her unpleasant way, then when she looks at you for a reply, you say "Oh sorry dear , I was miles away could you repeat the question. Keep thinking in terms of a chess match or a game of whist. The card is on the table and your immediate idea is to put X card down, but if you give yourself time to think you realize that you could play Y. She would be triumphant because she would claim that trick , and she thinks she is winning, but set a sprat to catch a mackarel and then trump all the rest of the tricks and she sits there wondering how that happened. Keep a little notebook at home (locked away so she cant read it) Make a note of what your strategy was that day and how well or not it worked. Of course you will not always win, and some day you may just snap and tell her what a horrible person she is and how no one likes or cares for her and she will end her life on her own. But when you turn it into a game, you can even award yourself marks out of 10. Did it go well and you went through with your plan 8, Did you lose your temper and not follow your plan 2 . Then you can tot up your marks over the years and see which was your best year yet!! If you have a close friend who knows her well, you might let them in on your new strategy and then you will have someone to speak to. You can even do it in front of her, as your friend can just say , oh how did last week go and you just say of about 3 out of 10 or whatever. I would think that she is so selfserving it will probably not occur to her that you mean the day you spent with her. Your friend may have someone in her life who causes problems , so you can just say at the coffee morning, Oh 10 out of 10 this week, or Huh 3 out of 10! If you think this might work do let me know how it goes. Of course as you become more and more adept at this, you will have more fun working out what marks you give yourself and she stops being the centre of attention for you. Hopefully as you become an expert at this, she will get more and more annoyed that she cannot win any more.Every time she starts on some horrible campaign you make Checkmate with a smile. At the very least thinking about whether this is worth trying out has given you a few minutes to put yourself in the driving seat. Good luck!