Head lice is at epidemic proportions across the USA> There's not much that can be done about it over all. Parents fight and fight it but if the parents don't know how to repel them then their kids will get them again and again.
The best thing you can do is get a spray bottle, a smaller one is best so you can change it out each day, put some water in it and add a few drops of Tea Tree Oil. I bought mine at Walmart in the ethnic hair care section. It's by the hair dye's and brushes in our Walmart.
Each morning when you go to brush your child's hair simply spray her hair while styling it. The oil stinks to lice and the oil coats the hair shaft. Their eggs won't stick to it so they die. I do this all the time and my granddaughter hasn't had them in over a year and a half. She is around the same people and just doesn't get lice anymore.
I suggest you go to headlice.org and study up about the proper way to get rid of them. Using pesticides is such a bad way to do this. Those pesticides are not good for anyone.
I did actually use one kind of treatment for head lice a long time ago and it worked really well. It was lice MD. It's not a pesticide but something else.
The site I listed above is a great site for information for all parents. I hope you'll share it with your neighbor. Even if you just say "OH MY STARS!!!! I found the BEST site for treating xxxxx for head lice....I just have to share it with you".