In Mary's personal letters....

[Eva Elisabeth]

There's obviously a letter Mary wrote to Mary Harlan on Oct. 16, 1869 in which Mary remembered Tad's birth as so difficult that "instruments were on hand when needed". Unfortunatelly it's not in the Turners' book (wanted to read this in it's context, most likely the letter was in the insanity file).

I just can't find any origin of one of the two stories about Tad's nicknaming and find that quite strange as these are so commonly "known".