I only wish this is the image I had my head.
"What do you want for lunch?"

"Grrrrl cheese!"  (this has always been pronounced by The Caterpillar exactly as written here; no vowels, just a collection of consonants resembling a word we thought we knew: "grrrrrl  cheese")

*teasing* "Don't you want boy cheese?"

"Dad, there's no boy cheese, only grrrl cheese."

*for the first time realizes she's been trying to say 'girl cheese' for the past three years and not 'grilled cheese'.*  "Uh, honey.  It's called 'grilled cheese.'  Not 'girl cheese.'"

"No.  It's not."

"Yes.  It is.  It's grilled because you grill it.  Girl cheese is something else."

"Oh."  

*short pause, then the inevitable*

"Daddy, what's girl cheese?"

*heavy sigh* "Well I don't know, but it's not a sandwich."