Curious about her genitals.

I remember reading from somewhere that toddlers are naturally curious about their genitals. And it didn't struck me that she has been "touching" herself or should I say poking herself until she screams pain in her 'kokopok' - her way of saying vagina - when I shower her these 2 days.
So, how do we stop our toddlers from poking or masturbating themselves?