This seems like a case of confirmation bias
For me the strongest thing you've said in your question is this:
I don't think that the player should be punished for rolling too well and her character is overall balanced on paper.
I completely agree; punishing somebody for happening to do well is absurd, and since her character is balanced on paper, this situation truly can be summed up to chance.
A thing that is likely happening here is people assuming "Oh, she always rolls well" and then only remembering or taking notice of the times where she actually does roll well; ignoring or selectively not recalling the times where she rolled averagely or even poorly. This is called confirmation bias.
What should be done? Nothing
Honestly, I don't think anything needs to be changed here, but I do have some suggestions. Actually record her dice rolls, you can see for yourself (using the Law Of Large Numbers) that her dice and her are rolling average just like the others. This would help remove the confirmation bias. You've said the physical dice seem to be fair, and if that is the case, I don't believe there's anything you need to do. I would recommend checking if the dice are fair.
In terms of the spotlighting issue, one thing to consider is also if her character is just making more rolls in general, this would mean her character is doing more things regardless of whether she is succeeding at them or not, which could be factoring into how her character is perceived by yourself and the other players.
Another thing that can happen is that you'll remember her getting "a success" but not the extent of the success. This is especially true in cases where there aren't degrees of success like attack rolls: you either hit, or you miss. Thus one could think of her as "always hitting the enemies" but she could just be getting lucky and be barely hitting them, a thing which people wouldn't recall.
What to do about being outperformed?
If the other players truly feel like they are being outperformed by her, and she really is a real life Domino (unconsciously controlling probabilities in her favor), then I think your best bet is to just discuss this as a group, and see what people think about it. They are your players and they know better than anybody else how they feel and what they want.
What I feel would be most important is to ensure the following point gets across: This is in no way, whatsoever, her fault.