Fleur

Fleur is designated as being "Rare" in English use, however it is in the Top 500 names for England & Wales. That designation should probably be changed to "English (British)" (like the names Demelza, Esme & company, Gemma & Jemma, etc.). [noted -ed]

Also Flemish: http://www.names.be/meisjesnamen.html?met=Fleur&sort=alpha

Also Judeo-French and Judeo-Anglo-Norman.
Source: Seror, Simon "Les noms des femmes juives en Angleterre au Moyen Âge".

I only knew one girl with this name. It is quite rare in France nowadays.

Between 1900-2006, 3421 babies were named Fleur in France. 158 in 2006. A very uncommon but old French name. St Fleur of Beaulieu (also known as Flora) is notable as is the Harry Potter character.

Why is the usage English when this is a French word and name? [noted -ed]

I have learned not to trust this site too much when it comes to the usage of a name. A lot of English names are used in the Netherlands as well and that's never stated here. I've never actually met a French girl named Fleur but I'm sure they use it, it's very nice!