Something else that could make the timeline work, could be if Fleur had insisted that she do a year at Beauxbatons at some stage, but for some reason Hogwarts refused to recognise that year as valid and therefore made her repeat it at Hogwarts, keeping Victoire in school for eight years in total rather than seven.

I think there's probably a lot of scope with careers for her. Both of her parents are fairly smart and talented (a curse-breaker and a Tri-Wizard champion is a pretty impressive combination) so she is unlikely to be stupid, and therefore could probably do most things if she wanted to. Perhaps with her French heritage (and presumably knowledge of the language), she might end up working for the Department of International Magical Cooperation, or as Bill's work probably exposed her to goblins at a young age, I could see her having some sort of Goblin Liaison role at the Ministry.