My mom thinks I'm a pedophile?

Showing my computer illiterate elderly mother the wonders of the internet, I showed her a picture of an old school friend's 4 year old daughter on facebook and commented on how gorgeous she was. Her immediate response was that she thought it was inappropriate that people put pictures of their kids online for anyone to look at. That kind of hit me where it hurts and seemed pretty inappropriate of her to say something like that. Why are some women such antagonizing bitches that way and how should I deal with them? Am I being over sensitive? No bitchy answers if you bitches don't mind thanks.