I feel like such an idiot/asshole and it's bothering me. Help?

Today I was doing volunteer work my mom's boyfriend take pictures for this rebuilding homes project in the area. We were on this one site and this really cute girl was fixing some child's play set thing. I was doing my thing by walking around and taking pictures. I tend to get nervous around girls like this and right before I took a picture in her direction she said "Should I smile?" really friendly. I guess I was nervous, I really don't know what was going through my head but I said "I want you to look like you're working hard." and I think my tone is what threw her off. She said "I AM working hard." I took the picture real fast, said Thank you nicely, and walked off, and I heard her give out a loud "PFFT." I felt like such an *** and it's bothering me all day. Do you think it continued to bother her? How can I get past this?