17-year-old refuses to invite her stepmother to her graduation party, leading to the resurfacing of older disagreements in the family: '[Her dad is] threatening not to show up at all if [her stepmother] isn’t welcome'

Handling huge shifts in the family dynamic early in your teenage years is one of the hardest things. You're just starting to build your foundations on how you see and determine your life, and suddenly those foundations are being pulled out from underneath you as everything you know shifts into an unrecognizable new shape. Before you knew that up was up and down was down, but now down might as well be up, and your dad has left your mother and the family for some new woman you don't even know. 

You might be upset with your parent in this situation, but they're your parent, and you have a history to fall back on with them. This unknown new partner, on the other hand, has entered into your life in the most ugly way you could imagine, and overcoming the feelings that take root at this point is going to be no small thing.

It's clear that this 17-year-old hasn't reached a point where she is comfortable or wants to be around her new stepmother, "Anna." But what is unclear here is whether or not she should be automatically able to attend the 17-year-old's graduation. As the honoree of her graduation, does the 17-year-old get to dictate, excluding her stepmother? Or is this a case where, being that she is a member of the family, at least the girl's father's family, she should be allowed to attend anyway? Is this a case where the parents enforce a hard lesson? Or would that lesson be the wrong one, and instead, they should respect their daughter's wishes, considering she is on the cusp of adulthood and will soon need to make her own choices? 

This mother is determined to stand by her daughter's wishes, and let's be honest, there are probably still some lingering bad feelings there as well on her part. But her decision not to invite her ex-husband's new wife has led to a greater rift in this family.