Wolf in sheep's clothing

Lucy is on the phone with her Grandma, the simple one. They talk for a while, in Korean. I'm not paying much attention, but I catch the following.

Lucy:   Why did you call, Grandma?
Grandma (assumed):   I was just bored.
Lucy:   If you're bored, Grandma, just do a puzzle.

Sure it sounds cute, but I fear it was more malicious. Lucy takes endless delight in the fact that her Grandma cannot do the puzzles that Lucy left in her house.