Sliver. Ouch!?

Okay, so friday night I was babysitting and we decided to have a bonfire. I picked up this piece of wood and got a big sliver in my thumb. The girl I was babysitting (she's 7) took a needle and got MOST of my sliver out. What happen's if you leave some of it in there because it doesn't seem possible to get it out? Will it get infected?