Sarah Rickard

[Gene C]

"And he was equally determined not to marry her (Mary Todd)
In fact, he was so dtermined that he proposed within a year to another girl. He was thirty two at the time, the girl he proposed to was half that age. She was Sarah Rickard, the little sister of Mrs. Butler, at whose house Lincoln had been boarding for four years."

from Lincloln the Unknown by Dale Carnegie. p63

The author seems to have borrowed a lot from William Hendon on the early life of Lincoln, so is there any truth to this?