LONG post but fuck I need advise feeling done with my MIL.

Hi All, First time mum, through my pregnancy myself and husband attended NCT and overtime formed an opinion on smoking and how we don’t want this around our baby. The only person whom smokes in our family is his mother. Overtime we have had conversations before our little girl was born with her to bring this to her attention, we handled this as sensitively as possible . Her home smells of it and so does she to the point my husband gets headaches when we have gone to her home previously and once during pregnancy and we both come away wreaking of smoke so never wear our best clothes and always shower when home. She gifted me baby clothes that were brand new in packets and it had even gone through that and smelt strong! She smokes 20 a day. She agreed she will not smoke on the days she sees us(so therefore has to be planned in advance) and she will no longer smoke in her home all for baby’s sake. We agreed and that was fine. My husband has had 2 talks with her, and myself I have on one occasion. I’m a believer in when touching on this subject it’s to go through him to avoid awkwardness. Anyhow she doesn’t drive and we don’t see her all the time. She has been to my house and come to see our little one but has to commute on the train which takes her just over 3 hours, after she did this a few times I thought let her stay for 2 nights because it felt like a far commute and my mum has stayed do I though I would be fair. She came to stay on a Monday evening and was going back home on the Wednesday. We had a lovely first day and came home from flower picking, my husband and her then went to local supermarket whilst I was at home with our baby to grab some bits and when he got there she got out the car and then lit up a cigarette…. My husband said to her mum what you doing I thought you wasn’t smoking on the days you see us & your staying!?… she said just having a cigarette he said mum we have spoken to you about this … we’ll be going back home in a bit and she will smell it. She then says to him “she will only know if you tell her”. Did you not think I wouldn’t smoke whilst walking from the train station to your home? Before I got here. Literally implying at the very start of her arrival she’s already done it and walked in our home and I’ve not stated I smelt it. Pushing boundaries! Trying to test me. He told her to go have a shower and that he would tell me when she goes home because his not lying to me and that his marriage will not be like that. He came home she was in shower and he told me I then had to fake being happy and like I didn’t know for the whole of the next day when I was quite mad about it. I am very proud of him for standing up to his mum but I feel quite upset that she did that and that I have been honest all the way through even if it’s awkward or difficult, I just don’t trust her now. Advise please, how would you feel. What would you do next. Since then 9 weeks has passed she wanted to see us I said we’re not free. Left it. She said she feels like she’s treading on eggshells and that same promise as before. I just don’t believe her anymore. She gave us a gift bag and in it is a cardigan tags removed she’s washed it and put it back on the hanger and in the back. Mentally I think I’m done here. What do we think I’m drainer and she’s already taken it upon herself to break our boundaries… step over us as parents and put my child at risk through her own selfishness.