Lydia age is given as 18 in the 1850 Federal Census at New Bedford, where she is living with her family (which at that time includes her stepmother). However, if the age on her gravestone is correct, she would have been not quite 15 at the time of the census in 1850.
She is the Lydia A. Boyle who is buried in Rural Cemetery, New Bedford, next to David & Hope Peirce. She died at age 43 y 5 m 6 d, and is buried with a 10-month-old "babe" named Hope Ann Davis. Is this her child?
Lydia A. Boyle died at age 43 y 5 m 6 d of Paralysis.