Anyone potty train before 24 months?

Two*True

About a month ago DD started telling the daycare staff when she had pooped so I bought kids potty just to have at the house.  I let her sit on it when she wanted which was usually just her playing.  That was fine by me as I had no intention of starting training.

Well while in Portugal she said 'poop', walked to the bathroom and stood by the toilet.  I lifted her on and sure enough she pooped.  She tried a few other times while on vacation but only the one was successful.

Then yesterday she did it at home and pooped twice on the toilet.  This morning she peed in her small potty.

So what do I do? I want to encourage it but I'm not sure if I should actively train or not.  She's only 16 months old but since she is showing so much interest I think I should go with it.

Oh and the cutest part - she has to have a piece of toilet paper which she then wipes with (even if she doesn't poop).