Second: all these things the author experienced can be said about any minority group, and women is just one of them in STEM. Therefore, can we really say that there is a particular bias against women, when the bias actually exists among many minorities? Therefore, can't we assume that really it's the monopoly of the majority that we should combat, and not specifically the gender gap?
Third, holy shit. If your self confidence is so low that any critique by a peer could shatter your world and cause you to abandon your career, you need therapy, or at least some kind of daily affirmation exercise. And being too afraid to ask to join a group is no excuse, for any person. You have to be able to work with other people.
Often times they will not be the same gender or ethnicity as you. Simply saying it's difficult or scary is not some big revelation: many people find it intimidating to work with groups of people they know nothing about. Luckily, that's what college is good for: overcoming those fears and becoming comfortable with what will eventually be a requirement of your job.
I agree with all her Eliminating the Threat points (even though that's kind of a harsh way of saying "Overcoming Obstacles")