OK, Jane has entered the early creative phase of 'wall paintings'... She did it a few times in our rental with crayons, and we were able to get that off with a brush and some dish washing detergent (which was good, since we were just renting the house and it was on the market and had regular showings. We would not have been happy if it hadn't come off). We put all the crayons away and I think it happened only one or two more times, but not as excessively. She was very good in detecting crayons that one of the other kids had left laying around :-)
Now we are in our new house and it is ours and I have become less vigilant with the drawing utensils. The crayons are still out of reach, but we have lots of coloured pencils lying around that the boys use a lot and that Jane and Tara like to use to to draw on paper. But of course, the walls are so nice and freshly painted, that Jane sometimes can't resist it and starts drawing on them again... I haven't tried to get it off yet, but would welcome tips of how to do it. These are just painted walls, but I think the pencil would have to be taken off in a different way than crayons.
Sometimes I catch her running laughing out of the room where we keep the pencils, clutching a pencil tightly in her hands, and laughing hard when I try to get it away from her... Redirecting to paper sometimes helps, but not always. Another day I found both of the girls happily standing on Tara's bed, both having a pencil, having a ball drawing on that wall....
I have gotten very good at recognizing the sound of a pencil drawing on a wall :-)