Letter from my mother in law

My relationship with my mother in law is.... Okay. I'm not the type of person that needs to be super close with my in laws, most of the live out of town/out of state. I'm not one to open up about personal issues to anyone other than my husband, my mom and my best friend. And even then I sometimes keep some things to myself. Anyways, I received a hand written letter from my mother in law saying how she wants to be closer with me (okay that's fine) but then she goes on to talk about MY FERTILITY and MY PERIOD and how I should get checked out by a specialist, get my hormones check etc etc. Like obviously I know all this, me and my husband have been ttc for 4 years and had a miscarriage in January of 2017, which she also brought up. When I got the letter a few days ago I read it in pure embarrassment and disgust. I told my husband about this and he initially said that his mom was probably just trying to be nice. Cut to today, I wake up and he said he read the letter and was absolutely furious. That it was such an invasion of something that is very intimate in our marriage. I also pointed out she never mentioned that her son needed to get checked out so the letter felt like an attack on me and I'm the reason we aren't giving her grandchildren (she's already got 5 grandchildren and 2 more due this year) She has no filter and no sense of boundaries.

She's coming out to visit in a few months when my sister in law is due and I'm dreading her stay with us. I don't know how I'll handle her visit.