mystery half solved

The kids have been taking the blame for this mess in the bathroom.  I've kept finding greenish blue stuff on the counters.

This happened a few times a day for about three days.  No one would fess up.

These pictures don't do it justice.  It looked like someone was washing marker off their hands and dripping the watery marker drippings on the counters.  This day though, I noticed what I thought to be little paw prints mixed in.

Well, that solves half the mystery.  We know who is doing this now.  Now to find out where she is stashing her art work collection and her art supplies.