To be sure, Barbara's ability to do that was surprising, a bit out of character, really, as Diane later points out...not sure what to do about that, except to keep with the idea that it was largely blind luck on Barbara's part.
It came across as more than blind luck, so you might want to highlight that. Example... say there's a virus on our work network. Well there's north of 5 million files on our various servers. Maybe I guess the file that contains the virus and get it right on the first try (1 in 5 million odds?). I may turn to my coworkers and say it was blind luck, but they'd all be thinking I had some secrets that I knew how to find it and wasn't telling them.
With Barbara, I got the same impression. I got the impression she thought it was luck but that it was really inner brilliance. The way James Bond will magically choose the corner to hide in that the villain will foolishly overlook. Bond doesn't know how he does it, just as Barbara doesn't know how she does it. Neither of them are no less brilliant for not knowing how they arrive at their results.
Not sure a good approach to fix this. By the time Diana can remark it's out of character, I'm pretty certain it will be too lake and the genius status will already be baked in. We'll see.
Jeb only understands the basics of space-time principles, Hadron colliders, and particle physics. His main concern is that it did work, not how it worked. Like Kyle in The Terminator, he could say, "I'm not a tech."
I got the impression he understands the basics, so that part was conveyed well. But you know... comprehending the (basic) nature of the curvature of space is not the easiest thing, even if you can't work out a time dilation equation to save your life. I get the impression that if he had to compute eigenvalues on a ticking bomb he was chained to, he'd make it out at least a few seconds before detonation.
Barbara's genius status was only in the plot device to have her operate the LHC and the hypydimentional event matrix. She becomes more the security officer and the friend as the story progresses.
Herein lies the fun. As far as the story's concerned, there's no difference if she had a temporary burst of genius or if she closed her eyes and pressed random buttons.
(granted, I have a limited view of the story so far)
Now that I think of it, she could even get the same effect by spilling her coffee on the control console.
Don't laugh, but oddly, I think sudden onset genius is the best option as you have it. Barbara's not really in my cross hairs because she's developed well
