Little Louis and Mireille are family.They both look very similar (same white fur, same Black Bead Eyes, same light-grey patterns around their eyes and ears) and are both mice. I'd say their brother and sister or at lest cousins.
Josephine has a YouTube account.She does want to be a reporter after all, and what better practice on a website where you can upload videos.
Zep or Bruller have seen One Piece at some point.Stéphane's superpower is identical, identical, to Foxy's Noro Noro no Mi power, i.e. emitting beams that slow things down. The only difference is that Foxy's Noro Noro Beam only lasts for 30 seconds where as Stéphane's beam lasted until his power wore off.