Why was she moving closer to me?

I was at a party Saturday. This lady went to sit across from me. We got into a conversation and she was showing me pictures of her kids as she is a single mother. I noticed she was moving closer and closer to me as her legs were touching mine and she didnt back her legs away. I didnt move mine either. She also seemed excited to know she was in my age group as I am 31 and she is 31 as well.