Thanks for the new chapters, Osis & RedHairedAnon! What a holiday treat!
I think the thunder chapter is really cute and true to the innocence and interest of these characters, and I think her parents are reacting realistically given that cousin relationships are legal just sometimes frowned upon in Japan. Especially in the sticks, it's more common and less pressured about.
I like the idol sister bonus chapter too, but I'll take main story content anyday over the side characters. The main kids are too cute together!