Aunt takes 11-year-old niece on vacation after her parents take her 4 brothers on vacation to Mexico, leaving her behind: 'We spent a day in Disney World, went to 2 Broadway shows, spent most of our time [...] on the beach'

As a parent, not every decision you make is going to be the correct one. And that, frankly, that's why having others in your life, parents and siblings, who are the grandparents and aunts and uncles to your children, is for. After all, "It takes a village to raise a child," and having others around broadens the scope of what your child is exposed to and can help keep you on the right course of parenthood. Who doesn't remember being able to go to their grandparents, or a trusted aunt or uncle, to talk about disagreements with their parents and gain a new perspective on issues they are facing?

As a parent, you're almost always going to have the right intentions, regardless of the outcomes. But, whether you have good intentions or not, there will be times when your kids just refuse to listen to you, and some other mentor is going to be the one they need to learn that lesson from. Having aunts and uncles around is great for this; they do, of course, know your parents as only a sibling could, and they're going to be willing to be a little more critical of them and offer some insight and guidance on situations 

Still, completely siding against or overruling a parent is always going to be dangerous territory. One should never seek to do so unless absolutely necessary, and when the parent has made the wrong call that is going to harm the child in some way.

With certainty here, deciding to take 4 of your 5 children on vacation and leave one behind is definitely the wrong decision. It would be one thing if it were like a sporting event or something in some mundane place that you wouldn't really want to visit, like Ohio or Tennessee. But to take 4 children on a destination vacation to Mexico, leaving one behind just seems cruel. Especially when you factor in that she had also requested to go on a girls' trip with her mother for her birthday and had been declined.