Palming ain't easy.
Errr... anyway, when you palm a card, you bend it and if your hands are smaller, you bend it more, basically. \SO even if your hands are a bit small, you should be able to do it just fine. Top palming is easy but it's unlikely to fool anyone (at least the way I do it), start there. Slide the top card of the pack by pushing it away from you with your right hand, using the middle knuckles of your fingers to create the friction. When it's about half way off the pack, press down on the tip of the card and bend your fingers inward to grip the card. Then you have palmed it, well done.