How many more minutes until I can come down?

I have the privilege of watching my sisters 2 kids on Thursdays. Every week, around 1:00, I put the younger one down for his nap and around 2, I send the older one up for "quiet time". I don't make her go to sleep if she doesn't want to but I have her stay upstairs for at least an hour.

Last Thursday, she kept coming downstairs to see how much longer she had of quiet time. I told her I'd come get her when it was time. This process repeated several times until I just started to ignore her. She then came down the stairs and handed me a note that said, "How many more minutes until I can come down?" I laughed and repeated again, "I'll come get you when it's time." A few more minutes passed and she came down with another note. She's in kindergarten and although she can read and spell most words great, she had obviously sounded out what she had written on the note. I was confused at first but I then sounded out what she wrote. It said, "I wrote on my door and walls." I immediately ran upstairs to find "How many more minutes until I can come down?" written on her bedroom door. As I opened the door, I saw a huge green heart written on her wall with a crayon. I looked at her and without saying anything (but obviously by the look on my face) she burst into tears and said, "it was an accident!" Indeed, it was not. An accident would have been a small line on the door or wall. But this was intentional. I used my sisters magic eraser (bless Mr. Clean!) and scrubbed the markings off. She asked if she could help but I knew if my 23 year old arms struggled to scrub, her 5 year old arms wouldn't make a dent.

It was hard not to laugh at the innocence of this 5 year old. But I sure hope she doesn't do it again.