Since you are uncertain there is anything there, I'd recommend LiceFree. It's non-toxic, and it comes with the best lice comb I was able to find at a drugstore. It's also billed as being preventive, so it's not a total waste of money if she doesn't have them. When you comb out her hair, have a box of kleenex handy and wipe the comb clean every time on a kleenex and look for anything that looks suspicious. Make sure you do this in the strongest light you can - sunlight is best.
It's the time of year when lice outbreaks are going around again! One of my friends called a couple of weeks ago to say her daughter had them. Luckily, my kids are still OK, but I've been using the Rosemary Repel line of products on them for the past month (www.rosemaryrepel.com) which might have helped keep the bugs away, who knows?
One last thing, which I hate to say - if you just look through her hair now without combing or using some kind of gel, you probably won't see anything. I thought my son was OK last summer when he was exposed and got them, but that was because it took about 3 weeks before anything showed up, and his case wasn't even that bad. If you think about it, it takes a while for one louse that crawls over to generate a lot of activity. (they have about a 10 day cycle, I think.)
Good luck!