Reincarnated with a special mind space & books of different techniques

What if Kushina wasn't Naruto's mom and Naruto wasn't Ashura's reincarnation. ___ At 19 Kushina and Minato considered the possibility that a female nine-tails container had a high possibility of having a stilled since the fetus will be in very close contact with the nine-tails corrosive energy. So they made a plan so they could have children but for it to work minato needs a "second wife", someone who they can have be a sub. for their children; more specifically that person's child; but that person will have to be of uzumaki descended and have child as well since if it's just that GROWN woman the energy would just kill the woman after a few months. I would like to specifically say that all credit goes to the original creators of the fanfic I'm making and I will be using techniques from different novel and manga so credit to them who created that manga or novel.