FTM seeking more advice

I love my MIL but she's crazy and not to mention on the old side which is why I'm thinking she's going senile. She's always wanted a girl but God blessed her with two boys. She wanted a girl so bad that she refuses to be that her youngest boy is her because she swear up and down they handed her a girl ( even though her boy looks exactly like her). Well, surprise, her favorite son (my husband) which isn't biologically hers (but still blood, adoption through the family, which isn't important, just going into detail) is having a girl. I know she's going to spoil the baby and I'm more than OK with that. She's put in to stay with us when I have the baby. She didnt ask, she told me, and she's always trying to move in. But I have a feeling she's going to try to control everything with the baby, hog the baby. She smokes bad, like a freight train. She has COPD, several stints, multiple heart surgery but she still smokes. Even though she won't be smoking around the baby, she'll still have nicotine on her, and it'll transfer to the baby. My husband says it's no big deal, but to me it is. Now that I have inform y'all on the situation. Should I just grin and bare it or am I going to need help? Ftm and have no idea what it's going to be like the first few weeks home. Any advice? Should I let her? Please tell me if I'm being petty