What she seems to hate is him being a lazybun and going through life like nothing matters. Thanks to Garam he changed, and is still changing, he's more grounded and wants to do everything right by Garam, she might be shocked at first but I think she'll pay it no mind after getting used to it.
Jaehyuk's mom is supportive (or at least tolerant) if she finds out about Jaehyuk being bisexual