Why do you think you have the right to tell another person on how and what they do with their body...
I grew up in a Christian house and to this day, if I tried to tell one of my sisters, niece's or female cousins what to do with her inside lady parts.. I would get dropped kicked in the nuts.. And told to mind my household and stay out of there's.
Because the baby is not their body. I can't help it if you and your sisters disagree and that they'd resort to violence because you might suggest we are all endowed by our Creator certain unalienable rights that include LIFE, liberty, and the pursuit of happiness.