Hi 2010BEBES,
I believe this was mentioned in a topic or two before, but in case it wasn't: yes, there will be a "child profile" function in the next version of LR (v3). This will allow you to create a profile for each child, and you just need to switch to the child's profile so LR will automatically keep track of that specific child's lesson playback statistics and progress.
Please note that we're currently working on LR v3 so we can't provide an exact date for when it will be available so stay tuned for updates!