Head lice help!!

My daughter's friend stay the night the other night and her mom called today and told us that her daughters head is full of head lice and just wanted us to know incase. I have checked my daughter's head and i found ONE BUG that is all no nits or anything but im trying to take precautions and want to treat her and mine and my sons hair but I am pregnant so I don't know what all to use I have swept all my floors, took all of the stuffed animals out of both their rooms, stripped all beds and in the washer now all the brushes got thrown away and I went and bought new ones but what else can I do I am freaking out my daughter start school on Tuesday and I do not want this to end up being a problem I'd like to bite it in the butt before anything more comes up any help would be extremely helpful thank you