Did Hermione ever un-obliviate her parents. It seems as though everyone forgot about that

I'm sure she must have, but it's not talked about in the books. It wasn't a big plot point in the books, it was just mentioned in passing, although in the movie, they made a bigger point of it, likely for the high emotional feeling during the scene.

Hermione cared very much about her parents. She had to obliviate them because she didn't want them to get killed during the war, and made them want to move to Australia and have new identities instead of being Grangers. She was powerful enough to reverse any charm she put on them. No doubt it took her a while to find them after the events of the book, but I bet it was near the top of the list of things for her to do. In fact, in Chapter 6, she says the following:

"I’ll find Mum and Dad and lift the enchantment. If I don’t—well, I think I’ve cast a good enough charm to keep them safe and happy. "

And, even more proof, here's a webchat with J.K. Rowling right after the release of the book:

"Maggie Keir: Was Hermione able to find her parents and undo the memory damage ?"

J.K. Rowling: Yes, she brought them home straight away.