I think the one you mentioned on your post about them picking flowers sounds the best! A video would be nice because I only have the barest of knowledge about FF7 XD

As for Peach, she can remember her first meeting with TEC (TEC being an AI supercomputer), or maybe being possessed by the Shadow Queen (if you want something more serious), or maybe if you want a silly memory her taking part on the quiz show with Bowser's minions XD