The more I've thought about it, the more it makes sense for Harris to pick Kelly as her vp.
He fits the safe white guy profile and from what I've seen of him, he has a way of getting his point across and being critical without rolling around in the mud. He would bring a certain kind of machismo with his background as former military and astronaut. I think he still owns and uses guns, even after his wife was shot and injured pretty badly, and because of that he could be an effective messenger on sensible gun reform. Even though people don't tend to base their vote on who the vp is, he would round out that ticket as the "cool" ticket. And who knows, maybe he could put Arizona more in play. He doesn't actually have any governing experience, but not sure how much of a consideration that will be.
Maybe she'll go with somebody else in the end. I may be wrong and I have nothing to back up the following statement, but I doubt she will pick Shapiro because I think she will be concerned about turning off some of her potential voters by putting a Jewish person on the ticket (despite her husband being Jewish and someone who could influence her thoughts/decisions, but I digress)