Hi sirenz, i give my DD a couple of prunes everyday to keep things moving. I break them up and she loves them, if you prefer you can mash them up in food. You can do that, or even some prune juice mixed into food is good.
Avoid consitipating foods like Banana, bread, etc. More fruit and veg is the go.
I also give my DD a little water with her meals. Mainly so she gets the hang of a cup, but i am sure it helps.
GL.