Ugh - we are just going through this. You can check my post from a little over a week ago. We definitely got some good advice.
Fortunately, I have a little boy. I found the best solution for a boy is just to buzz his hair. The problem stopped almost immediately for him once I did this, although I'm still continuing to comb out his hair to make sure there is no re-infestation.
Girls are another whole nine yards. Of course, I caught it off my son and, although mine was not so nearly bad as his, I noticed one week after the shampoo that I was getting a bunch of new ones. No matter how hard I worked to get out the eggs, I guess there were still a few lingering. I am hoping the 2nd application of the shampoo will do it for me, but I may even do a 3rd application next week. However, I am not sure I would do this on a child, since it is essentially a pesticide.
Someone suggested the conditioner/baking soda mix on the hair. I did this on both of us and bought the special Rid nit comb at the store - it's got a red plastic handle and thin metal teeth - I definitely recommend springing for it. You can either wipe down the comb with paper towels or run it under very hot water - make sure you get any nits or eggs out from in-between the teeth. Now that we seem to have the lice under control, I generally just wet my son's hair and use the comb - with the buzz it only takes around 10 minutes. I'm putting olive oil in my hair and it takes around half an hour. I haven't seen anything on me in the last 2 days.
I have also continued to wash our bedding and shirts/jackets daily. Someone recommended just running everything through the hot setting on the dryer for an hour and I've taken to doing that to save time/money.
I did notify his school immediately. Turns out he is the only kid KNOWN to have this so far. They took all kinds of steps to prevent spreading the lice and it SEEMS to have worked - keeping kids' jackets/possessions in plastic garbage bags, removing the rugs, vacuuming everything down daily and watching my son to make sure he's keeping his head off of everybody. It has been pretty embarrassing - although his teacher didn't tell anyone who it was, I'm sure everyone has pretty much guessed by now - especially since my son is telling everyone not to touch his head because he has "bugs". I know several parents freaked out at the idea of lice and a few pulled their kids out for a couple days. Definitely I feel like we're walking around with a scarlet "L" on our chests! :) Still, I felt it best to notify the school to prevent re-infestation. It would be kind of crappy not to.
I also told close friends (have actually been checking their kids' heads) and the mom of the neighbor kid my son plays with. Ironically, the only parents who pulled their kids away from playing with my son are the parents of the kids he CAUGHT it from! I understand they don't want to experience a re-infestation, but come on now. I was a little peeved by that, though I certainly can't blame them for unknowingly passing it along.
Just take proper precautions when she is playing with friends (no touching heads, put towels behind her head if she's sitting on a friend's couch, etc.) and it will probably help stopping the spread of the lice.