Lavazza1st. I can't believe it! Of course YANBU! Just because her culture does one thing does not mean your/our culture has to change. That is just manipulative of her! She is living in your culture! You have been very kind and generous! Of course you can't give up your job! Anyway, I deeply suspect that in her culture all families do not buy everything like that as they are trying to tell you! It would mean that all Grandparents would need to be extraordinarily rich, especially if they had several children!! Your son knows this is unreasonable. If they want this kind of free ride then they will just have to go back to her parents! Just tell them that! How on earth do they imagine you could afford all that and give up your job as well? Are they particularly stupid? No, this is manipulation. Stand up for yourself. Give them a time-frame. Three months to find a place to live because they must leave by then. That is a reasonable time in which to become fully responsible for their own family. That might hasten your son's attempts to find employment.
I think they are being very spoilt brats! Sorry to be so blunt, but perhaps it might help if you showed them what another person (me!) thinks of what they are doing to you! After all in her culture, her parents could just as easily turn things round and say she married a different culture so she has to accept their norms about who buys a house for them! In other words it works both ways!
I have to say, your son was very quick to give up his degree to be a father. Many people carry on studying, coping as best they can, knowing that the qualification at the end will offer them a better chance of a bigger income and more stable employment in the long-term.
They are responsible for their situation, they have to deal with it. They are lucky to have a roof over their heads at the moment and everything they needed bought for them. They should not take this for granted.
As for the nutrition of the baby, I do not know how you can alter a mother's regime apart from talking to her. How old is the child? Does she take him to the baby clinic? Maybe they could advise.
They may have got the wrong impression when you set them up so well here, but that was simply you being a very kind Grandmother. I know, I have done a lot of things myself which have been taken for granted, and I suspect they have taken you for granted here.
Hold your ground. Do make sure that they are not the only thing in your life, as well. They are using you and may well turn round and leave if they get a better offer elsewhere. Please make sure you have friends, activities and interests and your job. In other words a full life of your own which gives you satisfaction, especially if they were to depart. It is good for them to see, also, that you have a full life that is not just revolving around them and their demands.
Put yourself first please. Be firm. Never feel guilty about saying no. Regard your home as the Head Office of the Company you own and you are CEO. Let them see you have CEO attitudes in your home - what you say goes! Don't let them start endless arguments or battles. Just keep it simple. State that you do not pay for xxx. / You do not give up your job. /Of course the culture here is different and it is just as good. (not better - no competition - but it is a valid culture and your job and position as a woman is as important as any CEO who is a man in any other culture)./ You have your own needs and rights./ You have the right to be respected. / They must be responsible for themselves and their child like all other parents.
Just use the broken record technique. Don't explain, don't get upset, just repeat the simple honest obvious truth!
Wishing you everything good. Be strong! I feel confident in you! Please let us know.. 