Under "Mako Mermaids" show ( https://www.tvmaze.com/shows/4225/mako-mermaids ) we have "H2O" show marked as parent show and Mako Mermaids as reboot.
That looked pretty correct until I watched episode 3x15 of Mako Mermaids where one of the main cast from H2O appears as the same character and with same history as in H2O, years older. This makes events of Mako Mermaids show happen several years (5-10) after events in H2O so they should be connected as Franchise and not as Parent/Reboot.
Perhaps they didn't plan this when they started Mako Mermaids, but it turned out this way at this point in the show (which is just one episode before the series finale).





