one tree gives a baptism date of 26 Jan 1813 in Buckingham, Buckinghamshire, but does not provide a source, other than a vague reference to parish registers (which could be for the baptism or the marriage or both)
William Willmore, age 38, born in Akeley, Buckinghamshire wife: Sarah Willmore, age 30, born in Leckhampstead, Buckinghamshire daughter: Jane Willmore, born in Leckhampstead, Buckinghamshire