AITAH Refused to Pay for My Sister

Money. It’s be a tricky issue to tackle for many families. Some find it hard to figure out the right way to share their family expenses, others seem to have a problem with setting boundaries with their new partners, their adult kids, or even their siblings and parents. Based on r/AmIOverreacting and r/AITAH, featuring:
OP’s sister expects her to pay for them both. Fair?
OP believes husband doesn’t appreciate her input. Overreaction?
OP’s parents paying for her sister’s prom while refusing to pay for hers. Playing favorites?

[@lancerevell5979]

Story one....If Sis has no job, where do her "savings" come from? Their parents, I'd say. OP has no obligation to her. Sis needs to be an adult and get a danged job.
Story two, no. Hubby is supporting his wife and child, as is his duty. He has NO SAY in her novel.
Story three.... We know who the Golden Child is, for those toxic parents.

[@rJefff]

Interesting take on story two. Sure, the novel is the wife’s project, but don’t you think that pretty much everything in a family is a team effort? If it’s a loving and functional family, that is