They are out of line but your husband should be doing something about it! What has he said about it all?
She can’t force you to take anything. If she goes to put items in your hands, drop them and walk away. You don’t have to say anything to her at that point. Actions speak louder than words, separate yourself and your child from them. No one can force you to do anything you don’t want to. Lock your doors and do not let them in when if they turn up. It’s your home too and you should feel comfortable and happy in it. The fact they crashed your holiday as well, all they want is control. Write down every single thing they’ve done, it may come in handy for future if you divorce. Your husband should be putting you and your child first
This is hard and i am sorry you are going threw this. I would also suggest couples counceling/therapy. If you are thinking divorce then its time for some intervention and do some couples counceling. It may also help your husband to see how his parents are treating you is not right and help with a healthy compromise on how visits will look in the future and help him inforce boundaries with his parents. MIL blatantly being disrespectful and not listening is NOT okay. And he needs to back you up and call his mom out.
Yowza. I’m sorry. You and your husband NEED to be on the same page. Without that, the odds of your MIL and FIL accepting your boundaries aren’t high.
I am sorry your going through this. I dislike that children are really the most clear eye glass we get into the true colors of a lot of people and it tests a marriage. It's supposed to be a happy time. I was in this spot before, if you would try it I'd suggest couples counseling as it is hard as a spouse to bring practically anything up without the other feeling betrayed/picked on/ or a bias. I hope it helps. You hav every right and deserve people who can work with you to accomplish goals not knock you down to get theirs. I can't imagine my husband feeling obliged to "do things the way my family does" it's his choice, he is there for me not them... and I same to him.