There's a lot wrong with someone other than them saying stop (or go, for that matter). What business is it of yours?
42 is old and at that point she is at a high risk for having children with problems.
Do you think they don't know that? How is it anyone's decision but theirs whether it's worth the "risk" - and who are you to decide for them that having a child with a disability is worse than saying "stop"?
I heard some lefty women making snide comments about this situation.
I said “her body, her choice” and the look they gave me was priceless.