I’m not sure what she means by her neighbor providing fresh yeast. <<<
I think she might be talking about everlasting yeast.
There is the cake yeast, dry yeast, sour dough starter and a sponge yeast and everlasting.
I think the everlasting is what the pioneers used, it is like a sourdough, but not allowed to sour.
I know that my mom did not buy little packets of yeast, when we were kids, I have seen her use cakes of yeast.
Some where on this thread, I posted a bunch of stuff about everlasting yeast.
LOL, I am more asleep than awake, but here it is, a quick glance shows it was the Pioneer’s yeast: