In Mary's personal letters....

[Eva Elisabeth]

Toia, I just wanted to post quite the same - whether it resulted in a "chronic" damage/problem or not - obviously there was some difficulty about Tad's birth, and since Willie had his playmate and Mary's mother as many died in childbed it's understandable she (and her husband in order not to lose her) thoght that was enough now. As for the birth control and the (by some, like Tripp) suspected abstinence thentheforth it would be interesting to know whether Mary and A. L. also (despite the connection to nursing) knew about ovulation and conception.

As for your last question - I'm just at the very beginning (and also still reading two other books - all too fascinating to delay), so far not the but four children, but to word it plainly, he presumes that the Lincolns' sexual abstinence due to Mary's physical damage (a fact to him) from Tad's birth, plus the seperated bedrooms and frequent travels opened the door for a Lincoln-Derickson relationship for which A. L. actively sought the latter (being attracted to him at first sight).