My Moroccan MIL doesn’t bathe

I’m an American Muslim revert (person of color) and my Moroccan husband and MIL joined me in the US. Since arriving, I’ve noticed her hygiene habits are to bathe every 2 months or so, sometimes she goes for a month, sometimes 3 months. My husband has tried speaking to her about bathing more often, but she said she is used to the hammam and doesn’t like our bathtub. Her old routine was to go to the hammam every 1.5 weeks or so. She didn’t really bathe at home.

I bought her a hammam bucket, bathing ladle, and chair to mimic her hammam experience (she doesn’t like the shower), but that didn’t seem to help. My husband and my MIL have had a couple of heated arguments over this, to the point where she said she regrets having him. We don’t think it’s worth it to keep nudging her to bathe if she gets this upset. I’ve asked my husband to just let her bathe when she wants to instead of bringing it up. Is this normal for the older generation who’s immigrated to another country?

The problem is I’m currently pregnant and her BO makes me super nauseous at times. I’m at the point where I’m just gonna deal with my nausea because I don’t want to further upset her.