Looks like you were right, she definitely feels frustrated about being doubted and made to feel stupid. Hasn't given specifics yet, but I am sure I can get her talking at some point. She said she appreciates being able to bounce ideas off of me without worrying about the above. Good start I would say.
If this shit is what women have to deal with constantly, I am not surprised there are so few of them in my field. Why can't we all just get along?