Paul, the stepmother was Sarah Bush Johnston.

There is much evidence that Abe was born in NC before Nancy went to KY and married Tom Lincoln. Two women, one who died in 1890 and the other who died in 1900 swore they had held him in their arms before Nancy went to KY. Several people who knew Abe swore that his official birthdate of 1809 was several years too late. Austin Gallaher stated that he saved Lincoln from drowning in 1812 and at that time they had been in school together for over a year. Residents of Elizabethtown KY remembered Abe as a toddler, two years before he was supposed to have been born.

I suggest reading Herndon's book. It is very interesting and he traveled extensively gathering proof. There are more books with proof also that I have not read but intend to read.