After Voldemort was defeated she went to Australia where she had them go to hide under their new names and had their memories restored. So she didn't really make a sacrifice. Just protected them from being found by Death Eaters.
But during the nine months that they were oblivious, it obviously hurt her really bad. After all, she never knew when or if the world was going to end or if she was going to live long enough to get back to them. I mean, Harry and Ron and everyone else in the wizarding world had the same thoughts but hers must've been so much harder because of not only the uncertainty of her own and the world's fate, but the fate of two of the people she loved the most. They wouldn't mourn for her, they wouldn't even remember her, and that must've been awful knowing (and even if she did die and Harry or Ron had remembered that she erased their memories and they tracked them down to restore them, they wouldn't be able to).
I bet you anything that they were some of the people she was thinking of most when she was being tortured by Bellatrix Lestrange. That was moment when she was probably certain of her fate after so many months of uncertainty: death.
Kinda thought this was common knowledge if you read the book. Rowling MADE a big deal out of just how big a deal it was for her to basically delete herself from her parents lives. Doesn't she go off on Harry or something about the sacrifices her and Ron had made too? Been a while since I've read the books, but pretty sure it was emphasized how big a sacrifice she made
I bet you anything that they were some of the people she was thinking of most when she was being tortured by Bellatrix Lestrange. That was moment when she was probably certain of her fate after so many months of uncertainty: death.