Elspeth is about to phone her parents and tell them that she made it safely to her new house when she realizes on how many levels she isn't going to be able to do that.

One: she doesn't know who her parents are. She just has a vague parent-shaped impression that they were fine probably. They don't have names or faces or habits or histories.

Two: they aren't in her phone. Nobody is in her phone. The phone is as though brand-new.

Three: Now that she is realizing the above, she is no longer sure she should be telling anybody she made it safely to her new house.