I think you may have a slightly different product from the one I have, and I don't have much experience with Family Protection (I'm the only user on my PC). But I checked the settings in my version, and they're different from the ones in the previous version of Security Center. There used to be an option which would enforce Strict Filtering in Google's SafeSearch, including filtering of images. When I first got McAfee I played around with the settings to see what they did, and that filtering did work. I don't see that option now.
You say you purchased Family Protection - is it part of a McAfee package or is this a standalone product? And what version(s) of McAfee have you got? If this is a new version of Family Protection I'll have to find someone inside McAfee who knows how it works.