ESH some people are really superstitious and would feel buying a dead baby's stuff offensive and very bad luck for any child to use it. I don't, but many people do. If you had just put in your post that your friend had lost her baby to SIDS and needed money so you were selling her stuff for her, then the individuals could have decided for themselves if they wanted to buy it or not. I think you would have still easily sold the stuff, but it would have been a different buyer. I wouldn't hesitate to buy the stuff if I needed it, and would have been more likely to buy knowing a grieving mother needed the money. Buty you really should have put that info out there.

She's also being an asshole blasting it on Fb and Nextdoor and tagging you in her posts. She's being ridiculous, but I would bet she's one of those extremely superstitious people I mentioned above.