You're Free!

This happened 2 days in a row, so I thought I better write about it:
My girls were eating lunch at the kitchen table. When they finished, I cleaned their hands and faces and said to them,
"Ok, girls - you're free!" (meaning they were free to get up from the table and go play.)
KBH (age 3) retorted, "No, I'm four!!!!!" (note: when she says the word "three" she pronounces it "free")
Another note - she will no longer let us call her by her name. Instead, she insists we call her "Big Girl."
*sigh*