My sister did it.

As we were driving to church today, Joel turned around and saw that Gabbie had drawn on the inside of the van using the chalk from her purse. He asked her if she had colored the inside of his van with crayon.  She corrected him that it was NOT crayon, but was chalk.  Then she said, "I don't want to talk about that." Ultimately the blame fell to Lilah, even though she sits on the other side of the van.

Then I turned to take this picture and she tried to cover it with her hands so I couldn't see it.