Thank you all for your expressions of concern; all have been duly noted.
I believe there is little or no risk that Jenna would report me to her supervisor or to HR. The chances of that are so small as to be effectively zero.
And, if I were fired, I believe I could easily find similar employment elsewhere.
I believe there is little risk of anything bad happening to the keys as long as I’m there to keep an eye on things.
I believe it WOULD be somewhat high-risk to store the keys at work overnight, or at anytime when I’m not there.