So Fleur is either an animagus or gets cursed for a bit before Harry's first year at hogwarts. She ends up in eyelops owl emporium, and guess who sees a snowy white owl and gets it? Harry via Hagrid. Enter the reallt convoluted way to get them to be frien…
Another random idea: Harry and Fleur are internationally famous art thieves in the vein of the Saint, Arsene Lupin, and Lupin the Third + Fujiko Min
Painter story. Harry takes up painting summer before fourth year as a creative outlet for trauma. He asks Fleur to be his model. Hilarity/depressingness ensues.
A Death In Paradise style AU where stuffy Auror HP ends up getting transfered to a tropical French territory, and ends up being partnered with the sultry and sarcastic FD