Spoiler Alert
Overall I liked the episode, getting backstory is good.
Alas when giving Gwen a friend, and then have that friend be emotionally manipulative in the episode, it would have worked a lot better if you had, you know, established her BEFORE this ep.
As for Gwen's mom... wow, self-absorbed much? So you procrastinate about the invitations and instead of being the adult you guilt trip your daughter, who is busy with studying and saving the world into handwriting them for you and then call her constantly at school to nag her about said invitations, telling her that she'd better not be saving the world before she's done doing your work...okay then.
I am highly amused as to how much mom hates the other side of the family. Given, they are pretty much all douchebags.
As for Kevin, so, dear creators, you finally made up your minds as to whether he goes to school or not.
I was a bit weirded out though, that after watching people dump work on Gwen there was no lesson on: How to say no!
Or even a: You need to appreciate Gwen more. It seems the morale of the story is: Heap as much work and responsibility on Gwen as you like, she can take it. WTF