There's always a fair amount of French Maid cosplays in Anime Conventions that I find it hard trying to keep up with all of them.
She looks like she's cosplaying a specific character with the details she put into her hair and the straps on her leg. I'm wondering if that clip on her apron was also done on purpose. Compared to the other French maid cosplayer I feature a while back, I think she'll be easier to guess.
EDIT: Thanks to anonymous for leaving a comment saying this is Izayoi Sakuya of Touhou Project! I hope people leave their names next time, though.