My grandmother's sister was also a preemie, born on a farm in rural Indiana. Her bed was a shoebox on the oven door. My great-grandmother could slip her wedding ring over the baby's fist. Aunt Vi is now in her nineties.
My father-in-law was the same -- they kept him in a shoebox by the stove or the fireplace. I think he also weighed two pounds -- he's 74 now.
Isn't it great what happened even before medicine got to today's level of sophistication?