Yep, you're all bang on, of course, in the sense that I don't have to feel guilty about her emotions or nervousness. I have figured out that I have a trigger about this kind of situation since being in a poly relationship years ago with a couple. When my girlfriend would get triggered, she enlisted our boyfriend to help her, in effect, punish me for how she was feeling and this has resulted in me being more stressed than I should be when I feel like "oh no.. it's happening again!"
Fortunately, I've been able to communicate this to my current partners.
*deep breaths and letting it be for now*