Context: I'm pregnant with my first child. My mother-in-law lives abroad. We've already had some difficulty with her not respecting my visitors boundaries with the newborn when I asked her not to book flights too close to my due date, because you never know when the baby's going to arrive. She went ahead and did it anyway, so if I go to 42 weeks, she'll arrive in the country 6 days post-birth. And was planning on staying in our house (despite me saying that's not going to be possible. She now isn't staying with us. But that's another story).
Main query is that I'm now really worried that she and her husband will catch something on the plane on the way over and give it to our newborn. I'd ideally like her to not visit for the first 2 days after getting off the plane, so as to avoid her spreading germs. Is that unreasonable?