People look at me like I'm a Child-Molester when I'm with my Girlfriend, what do I do?

When I go out with her people always give me weird looks and look like they think I'm some kind of pedophile. I'm 30. And she's actually 25 and proved it but she seriously looks so much younger, she's petite and has these beautiful natural girlish features and perfectly pure skin. She's truly beautiful and seems ageless but its often a source of awkwardness for me. For example, We visited this new synagogue (she's Jewish) and this guy asked her if she had had her Bat Mitzah yet (a right of page ceremony for a Jewish girl when she's 12), like he thought she was 12, and then asked if I was her father or uncle which made me feel very awkward. I really love her but I always feel very awkward, how do I get over this?