A what?

I treated my six-year-old niece to her first manicure yesterday. When my manicurist asked what shape I wanted my nails, and then proceeded to suggest square before I could even open my mouth, I tried to delicately tell her I didn't want that shape. I then searched for an alternative word for "hooker", knowing that Miss Inquisitive would ask what that meant. So I said, "lady of the night". My niece whipped her head around beamed widely, and exclaimed, "Hey...that's ME!"