Good old fashioned common sense. And like you said with the salts. She knew enough to not cut the salt from a new mom. She realized that with all that fluid loss and hard labor the body needed salt and sugar.<<<
Common sense is priceless.
There is much to learn, from a good teacher, and today so few even know the things that your midwife knew, without a fancy education.
Interesting thing to note, my midwife had been an OB nurse for 30 years before moving to Texas. Had delivered babies since 1948. In my original post about this I said something about recommending home births when there were no complications. I did actually have a complication that would have likely resulted in a C-Section had I been in a hospital. My mid-wife was not even fazed. She knew what to do and delivered safely. Only afterward did I discover that a hospital wouldn't have delivered normally. The umbilical cord was wrapped around the baby's neck 3 times. My midwife just as cool as a cucumber just said, "oh all we have to do it loop it back over the head and we're fine. She did the unlooping as quick as an experience crocheter does 3 chain stitches.
So, how many of those day to day things have been lost by simply coming up with something dangerous and more complicated as an alternative? I think lots in all areas of living. Something to remember and think on when we see "progress."