Fleurs parents would love for her to have a little sibling to play with but they have trouble conceiving so they turn to adoption. And see here this cute little boy that was left on the orphanage doorstep just two days ago on november 4 1981. Harry grows up with the Delacours and they even get a new little sister after a couple years. Eventually they figure out Harrys true identity for he gets a letter to attend Hogwarts. Fleur will fall in love with him without realizing since he is the only guy that isn’t weird to her and becomes quite an overprotective yandere sister while Harry stays oblivious.
No Voldemort since all the horcruxes failed when the AK backfired. Just a fluffy, funny fic.