My wife is a Boustead but her line is back to John Boustaed born 1840 in Cumberland. This appears to be a different line to that of John and Isabell as I have not been able to find a link.
However, we do have some information about your line from a letter passed to my wife's family some years ago. The copy we have is unsigned but was sent from Cottage Grove, Iowa by a grandson of Robert Blaine Boustead. It contained the following: -
"JOHN BOUSTEAD - born in 1812, the 4th child in a family of 7. His parents were THOMAS BOND and KATHERINE(TAYLOR) BOUSTEAD.
JOHN BOUSTEAD and ISABELLA (BLAIN) BOUSTEAD had the following children: -
THOMAS BOUSTEAD, born 4 October 1837 at Orton, Cumberland, England. ISABELL BOUSTEAD, born 20 July 1840 at Orton, Cumberland, England CATHERINE BOUSTEAD born 17 October 1842 at Newcastle on Tyne, England EDWARD BOUSTEAD born 22 October 1844 at Newcastle on Tyne, England JOHN H L BOUSTEAD born 17 february 1847 at Newcastle on Tyne, England ROBERT BLAINE BOUSTEAD born 17 February 1852 at Newcastle on Tyne, England ELIZABETH BOUSTEAD born 1858 - died in infancy.
JOHN and ISABELLA (BLAINE) BOUSTEAD and their family came to America in the fall of 1868 landing in New York Harbor on October 14. Isabella diedJune 16 1869 at the age of 78 years."
The date of Isabella's year of death is presumably a mistype as that would have made her to be 67 at the birth of her last child.