In what world is she entitled to presents from people she openly resents? 

Who should you buy presents for? If you’re a childless person, you might have kids in your life that you want to buy Christmas presents for, even though you don’t technically have to. Your friend’s kids or your siblings’ kids are worthy candidates for gift giving if you’re close with their parents and want to cultivate a strong relationship with their kids, too, but it’s by no means «required» for being a good adult in their lives. Having a good relationship with them without bribing them with extravagant gifts is so worth it, especially if they’re good kids.

If you have a large family, it’s virtually impossible to buy gifts for everybody. If you have 5+ siblings who all have partners and kids, you might feel pressured to buy 20+ gifts for every family member at Christmas, and that’s just insanity. Even if you decide to buy presents only for the kids, it’s still going to be way more expensive than it needs to be. There isn’t a clear solution, but it might be easier for parents to buy most of their kids’ Christmas presents. 

The aunt in this story has bought more presents for her step-niece than any aunt in the history of the world has ever bought for a step-niece. Expensive birthday and Christmas gifts aren’t enough for this girl, and she thinks that her aunt should’ve bought her a car when she turned 16. What a brat!