Oh you poor thing, you have been a lot more patient than I would have been. There comes a time when you have to put her on notice and tell her she has exhausted your patience and you won’t tolerate any more nastiness and disrespect. If she wants to be part of your lives she either accepts your wishes, whether she approves or not, or she will be excluded from your and your child’s life, your husband can have a relationship with her, without you having to put up with her behaviour. You can’t let her make you anxious and stressed. I suspect at the heart of this is jealousy. Instead of being happy that her son has met someone who he loves, she is acting like a jealous ex, some mothers are so possessive that is what they do.
I am lucky, my son’s partner is lovely and we have become good friends, if she has a day off she often rings and we go shopping or have lunch, their new baby is due next month, my first grandchild and I couldn’t be more excited, she has two lovely children from a previous marriage and needs no advice from me, but I wouldn’t volunteer any unless I was asked, it’s her baby and I will respect her ways, will visit when invited, and being a clean freak would be horrified at anyone going near him if they had anything infectious, as for kissing a baby on the lips when you could pass on any bugs, that’s an absolute no no in my book, but it’s up to his mother to decide, not me. Her mother and I get on great as well, no jealousy or competition and that how families should be. I feel sorry for you that you have this awful woman to deal with.
I hope you can reach some kind of agreement with her, but some people are just plain nasty, and it’s not your fault, it’s down to her, so please don’t let her make you miserable.