OK...yeah that's pretty clueless, that she would say that after you talked to her about being alone, and it actually says a lot about her own insecurities...that she would think that there was something "wrong" with eating in a restaurant by herself. I do it all the time, and honestly I love it. I get to pick wherever I want to eat, without consulting anyone else. I don't have to make boring small talk. I can play on my phone without being rude. Personally I think that you are likely a lot more self-confident than she is...at least in that area.