As I tech journo I go to lots of events where, besides the PR staff, I am the only woman. I can relate to all of the scenarios you describe. Like most journos, I also do some copywriting work for startups with a more technical writer (we compliment each other’s skills I think), and the meeting you described of the client facing yourself and not your female colleague is a common problem. Even when my colleague will be saying things directly to them like “Cate will be covering that bit”, they will sometimes not even look at me when speaking.