I'm not so sure that temperature is the issue...but I agree that this particular snake appears to have some massive kinking in the spine...about halfway down the back, and right near the cloaca.
She is a beautiful snake, admittedly, but I would watch the rest of the babies to see how badly kinked their spines are. It could be a genetic issue, or it could simply be an individual snake issue. If all or most of the babies are kinked, I would recopmmend breeding the parents with different partners next year, to try and see if it is, in fact, a genetics issue. One or both of your parents may be susceptible to short-tail or kinking issues.
Also...unless I am sadly mistaken...incubating the eggs inside the viv shouldn't be much of an issue. Your incubator would be set for around 85*F...just like the warm end of your viv. Shouldn't be an issue, IMO. The temps for incubation and comfortable housing are so similar that the differences would be inconsequential...from what I understand. I could be wrong, but the main issue would be incubation time. Lower temps cause longer incubation periods. And in the viv...the temps would fluctuate more, causing prolonged incubation periods, for sure...but would it really be causitive of such kinking in the spine? I don't know... :shrugs: