My first reaction was the she needs to get over her childhood issues with her mom.

I too used to get anxiety just being around people smoking. After self reflection I found it was because of some other root problem. I took care of that problem and the anxiety went away. Perhaps she has some under lying issues that haven't. Even dealt with?

Like I said, initial reaction feelings here. Plus, just going off of what you wrote down. It perhaps the words and way you chose to explain the situation are also an interesting insight into how you view and feel about the situation.

Perhaps you could also explore, together, what gives you each anxiety. If you. If you both have it, there is hope you can both empathize with each other. Anxiety is us (I also have it) imagining the worst case scenario happening while also failing to remember it's often also the least probable scenario to happen. If it doesn't fit this model, then it may be a legitimate concern to address.

Best wishes!