Background: I am a junior postdoc who has been working for some years with an overseas collaborator who is much more senior. I have previously had no issues at all with this collaborator. For the last few months, I've been working on project A. I came up with the idea for project A on my own, and have been leading the analysis - my collaborator has only been involved in giving me feedback during meetings. Meanwhile, this collaborator has a PhD student at her institution who has been working on project B. They are under a lot of pressure to publish project B, as the data on which it is based becomes public in a few weeks. Projects A and B are similar in terms of the methods and the type of data involved, but use entirely different data sets, and are focused on entirely different systems which are in themselves not similar at all.
A few days ago, I gave an update on project A during an online meeting. In attendance were myself, my collaborator, and some other collaborators, including a couple of people I'd only met once or twice.
As soon as I finished giving my update, my collaborator became quite upset, seemingly out of nowhere. She said she didn't like how similar project A is to project B, and sort of implied that I'd piggy-backed off her PhD student's research, and said that I needed to add her student to the paper. She said we need to protect grad students in the current environment of fast-paced research (which I 100% agree with), and that she did the same for me when I was a student (which is completely true). As all of this was happening my body kind of kicked into fight-or-flight mode, so I can't actually recall anything she said exactly, but the way she was talking, she was clearly very exasperated. It got so heated that one of my other collaborators interjected to defend me at one point.
In the moment, I apologised profusely and said it wasn't my intention to "scoop" her student, and that I'd add them to the paper (which honestly doesn't bother me).
After the meeting I was extremely shaken and upset. The things she said really hurt, because project A is really the first project I conceived on my own, and I had been feeling positive about the work I'd done. I also felt like she'd humiliated me in front of my other collaborators, and that she'd possibly tarnished my reputation in their eyes, particularly those I don't know very well.
The thing is, I don't really understand where she is coming from. I only became aware of the details of project B about a month ago, after I'd already completed most of the analysis for project A. I absolutely did not take any ideas from her student to use in my own work. In fact, the analysis I've done for project A is similar to previous projects I've worked on with this same collaborator, and are not anything particularly novel. Also, she's been aware of project A for quite some time, and has never mentioned getting her student involved up until this point. Finally, in my opinion, project A and project B do not really compete - they focus on entirely different systems and use different data, so I don't understand why she thinks my work is threatening that of her student. If anything, they complement each other. I suspect she is feeling a lot of pressure to publish project B, and I wonder whether I might have just caught her on a bad day.
My question is, should I say something to her about how I feel, or should I just let it go? I've been turning it over so much in my head that I really need an external opinion. I want to clarify why exactly she is upset with me, to explain my perspective, and to let her know how she made me feel. However, I'm afraid that if I talk to her about it, it will only make matters worse. What should I do?