When is it necessary to intervene.

So, a friend of mine has a sister with a history of severe mental illness. She is around enough that I know her pretty well. She had a boyfriend for less than a year and randomly got pregnant which shocked everyone to begin with, but now has a sweet innocent 4 month old baby girl. She continuously posts pictures of her 4 month sleeping wrapped in Blankets in her crib face covered, and even after pleading from fellow moms refuses to try to make the crib safer. She has expressed she feels the need to leave her boyfriend but got engaged instead despite him being sexually aggressive with her after labor. They aren’t financially responsible or stable and decided to get a snake now?? When is it time to tell people to cut the shit when an innocent baby is involved.