Gamine is a noun that refers to a girl with a mischievous, boyish charm.

Coming directly from the French word for ‘street urchin.’  gamine was introduced to English speakers in the late 19th century. Gamine can be used as a synonym of ‘tomboy.’ Here’s an example:

My sister always had a boyish charm that got us both into a lot of trouble. Having a gamine for a little sister certainly got me into a lot of playground fights.