Welcome back ladies and gentlemen of the internet. Family should always be there for one another. Being able to rely on relatives, parents, and siblings is the beautiful thing about family, but of course there has to be a boundary drawn somewhere. If one feels like they're being used or manipulated, it's time to stand your ground and let the person know where they're not allowed to step.
In this Reddit thread, the original poster (OP) is a woman whose pregnant sister is demanding more from her that seems appropriate. OP has two young children, and they each have themed bedrooms. When OP's sister becomes pregnant, she suggests that OP give her bedroom décor that's currently in use; things like OP's daughter's curtains, blankets, and other furniture items. OP obviously refuses, saying she's still using these things, but she's met with hostility from her pregnant sister. The sister deflects by calling OP greedy. If someone accuses you of something, it's probably because they're the ones who are actually like that.