I was horrified when my kids first got lice in their hair but there’s nothing really you can do to prevent it completely. You can help to try and stop it by the methods of the previous comment but this will be an ongoing struggle until they reach high school. If there’s one child with lice that their parents don’t treat then it’s an ongoing problem. The solutions from the chemist are really harsh on their hair and I’ve used conditioner and combed and combed until no more lice. It works if you can spend the time.

It’s so frustrating…. I hear you
Treat with kp24 lotion and comb
Keep girls hair tied up in a ballet bun smothered in gel
Teach kids not to put heads near other heads
No hugging or heads on beanbags or dress up .
Soak hair brushes combs and bands in sink in boiling water
Repeat weekly