My 3 year old got lice! What do I do?!

I can't believe it. I was changing my daughters clothes when she was complaining that she was itchy. When she was scratching her head, I told her to stop and let me look. And there they were! At the base of her neck. I have no money right now, and no lice comb, so what can I do to get rid of them? I don't even know how she got them. She stays here all the time with me, and we go outside every now and then. The last time she saw another child, other than her sister, was a few weeks ago. So why, all of a sudden, does she have them? I' so frustrated, what do I do? If anyone knows how I can get rid of them, please tell. And remember, she's only three.