I just got through watching a pair of Lu-Hi games, just to see what the baseline for Heckel is.
First, she's got a motor and she brought this with her to USC. She's almost at the level of the Havoc Twins and will be a good addition in that area.
Second, she's a pretty good scorer, though not noticeably better than KK and definitely not the perimeter shooter Ash was already in high school. Both she and KK need to improve in this area. She finishes better than Ash at the rim, though not better than KK.
Third, she's a pretty good passer, but again not better than KK.
Fourth, she's athletic, but not nearly as strong as KK. Maybe some time with Andrea in the weight room will help with this, but currently she's rather slighter than KK or Ash.
If Geno persuades her to come to Storrs, what he's getting is a second KK, and that is a really good thing to have. In fact, he's already getting a second KK in Kelis. So he'd now have three KK-type PGs. Overall, I think having 4 really aggressive defenders to rotate in and out will be really useful.
If it were me, seeing what Kayleigh has done this year at USC and assuming she's gotten up to speed at UConn, I would still start KK over her at PG. They are both high-motor players, though KK's motor seems to rev a little higher. I'd want to save her as a 6th woman to bring a fresh jolt of energy along side Ash. If KK starts, she might not be able to be quite so 'maniacal' on defense, if only because she'll need to conserve some energy (and fouls) in case she's out there for more than 20 mins.
Finally, given the 3 year time scale, Kayleigh's role would be bound to grow each season until she's the primary PG. If next season the starters are Azzi and Sarah (and probably Serah), with KK and Ash starting in the backcourt, Kayleigh would still get lots of minutes in a system that is very fair. Nika used to say, "everybody eats" though it might be more accurate to amend that to "you eat what you kill." I suspect that's a system Kayleigh would be comfortable in, as would KK and Ash.
Gradually, the Storrs mentality will become Kayleigh's mentality, and I think she'll enjoy that very much, especially if it comes along with a couple of rings.