Montessori Beginnings- pad locks

A few weeks ago I gave F and C some pad locks to use. They got them figured quickly. Today while I was getting things ready R picked up the tray with the locks on it. I just let her as I wanted to get things done before the others woke up.

She worked at it for a while trying different keys and watching it open. I don't know if she completely understood that the keys were different. She just kept working.
We will be playing with these again.