It's like Adam doesn't like the resting mechanics! Remember back in the day when he and Steven hacked the hell out of resting and travelling in 5E, tried, reworked, dismissed all sorts of ideas? I bet some of that stuff stuck around.
However in this instance, the interruption and splitting of the group made for a very intense episode. Berg discovering the 5 finger discount while on his literal last breath was hilarious!
I vote in favor for allowing it!
The reincarnation cycle evaluates the amount of Karma and Dharma of the entire lifespan.
We know only a little episode of her life. She was heroic in the end, but maybe she was not good enough to ascend into a higher form? The fact that she became a farm girl might have nothing to do with her race, but purely with the timing of a person being born, when her soul was ready to redeploy!?
Also keep in mind that (to my knowledge) Genasi, Dragonborn and Aasimar are on the same level of ascension. The next step would be what? Demi-god? Deity? Maybe a soul just has to grind through many lifetimes at that point to collect enough Karma for the next upgrade.