Easily ret-conned by saying Natalie's parents decided to remain divorced.

@Strannger18 said:

Natalie's father was seeking another woman and everyone says he was cheating. But didn't Natalie say in season one she faked being sick because they got divorced, so her parents came, they started talking, he moved back home and she hoped they might get married again?

I thought that was Jo who did that, but they didn't get back together.