I’ve been putting off the multiplayer quest… and question about Retsuko!

Can someone visit my island so I can get it over with lol please and thank you! I thought I could just keep putting it off but now it’s starting to bother me that there’s a quest I haven’t done 😂

Also, why is retsuko sooooo hard to level up?! I’m trying to do the swimming lessons quest and I’m barely on level 15 with her and I’ll give her 3 heart gifts and it BARELY works. 😭 any suggestions??