I feel for you familyforever, i was trying to conceive a second...never happened, and my SIL, who had 3, went off bc and got preg (the very month i told her i was trying) what was most hurtful is, she's not even good at parenting, didn't have a room for the baby, it was a girl, she had 3 boys. 2 bedrooms ...no home study for her! okay sorry, didn't realize it still bugs me...
my bio-sis, has had 11 pregs, 4 kids, and only has one.
so i feel your pain.
i would nicely say something, using "I feel" which generates the least defensiveness because deep inside
i believe people have to know to some degree that you may be hurt. esp your MIL, mine was the same except it was "i want a girl (gdaughter), a girl"...i would say,
i would want healthy, healthy to let her know how i felt. by the way, i had 2 girls at the time...
you could move, i find visiting is so much more enjoyable.
Best of luck...i hope you are blessed immeasurably more than you could imagine.