The Online Family answers:

You do have something to be concerned about if your friend's web site has personally identifiable information posted on it as well. The sad fact is that some dangerous predators use the web to find kids to harm offline. So make sure your friend's site has no way to identify where she or you live or your full names. The kids' clothing or surroundings in the photos, such as a school, should not reveal where they live or hang out. The file names of the photos shouldn't include their names. If she has her own ".com" web address, she needs to make sure that her domain name registrar record, which are public, does not include her address or phone number (by default, many do). When in doubt, if you're still really uncomfortable, ask your friend not to post photos of your kids online.