OP here to answer a few questions that have come up. I spent the whole time inching away but she didn't seem to realise there was anything wrong. Also no I did not call her out because she was 10 years older than me, twice my size both vertically and horizontally, and accompanied by her husband. Also I'm a coward and socially awkward and tend to avoid confrontation wherever possible. Seats at the TEDx were assigned and I paid for nice stall seats, I wasn't going to move. Even if I wanted to, the place was packed with 1800 people so there was nowhere to go. To whoever said she wasn't interested in the conference, it seems like she was. It was actually quite annoying because she kept making comments out loud throughout the talks: "Cool!", "Wow!", "Who'd have guessed?!". Which in itself is rude because talks are about listening and not interfering with the experience people around you are having. Any other questions, feel free to ask!