My kids had lice once (and ODS has been in daycare/school for the last 9.5 years) and honestly, it is not something to panic about. (PS. I didn't do any bagging and no more lice in 2 years.)
YDS has had a kid in his class sent home every week for the last month due to lice, and I've haven't thought once of keeping him home.
Yes, buy yourself a terminator comb. Once a week in the bath, douse your DD's hair with cheap conditioner and comb through wiping on a paper towel. You will know right away if she picks some up and this way, you will most likely never have to deal with it.
I do this about once a week now just to be sure and all clear! I do a more thorough comb out if there is a report of lice or if my kids will be attending something with a lice check (i.e. camp).
Sweetie Pies, DS 9/2004 & DS 4/2008