
I think it's because of the kids they shared, she was able to understand their language. Similar thing happened in the manga Red River( time travel)

I mean kiss *

I meant an explanation for it.
Yeah, there could be those theories but it wasn't explained to the less knowledgable readers, especially since the scene shown that she woke up confused and was still unable to understand but just a few seconds page transition, she suddenly was able to, and even the characters herself didnt find it strange.
What, the author didn't even put efforts to explain why she suddenly could understand their language? Like it wasn't the most emphasized thing in the first two chapters.