Argument question with friends and family

I don't do this what so ever but my friends and family who do, do it find it ok...

Some of my friends and family smoke weed some of them did it while they were pregnant. What is your guys intake about that? I keep telling them that it's not safe but they turn around and try to prove me wrong by pulling things off the internet or how they turned out after there mom smoked weed while pregnant with them or how their own kids turned out just fine.

Please no hurtful comments I just want to know what your guys opinions are since my friends and family's are pretty strong