Oops. My Bad.

Today, my neighbors several houses down were walking by. They walk by every afternoon. I've never been outside to say hi, but I see them nearly every day. I've always thought how cute it was that the grandma and great grandparents took their twin granddaughters for a walk along with their two identical hound dogs. Anyway, today we were out working in the yard and they stopped to say hi and ask about the kids. I told them Patrick and Kimberly's names and ages. She said her name and introduced me to her parents (who look to be in their mid to late 80s). I then said, "And these must be your grandaughters". I was totally wrong, they were hers. I didn't know if it would be best to apologize and bring more attention to my blunder, make excuses for why I couldn't tell her age, or move on as if I never said it. I chose to ignore it and asked the girls names and age. But, I am so embarassed that I stuck my foot in my mouth. It's one thing to think someone's grandkids are their kids (this happens to my mom all the time) because it's a compliment to how young they look, but the other way around is terrible. I hope she wasn't offended and will still talk to me when I see her again.