I am not related to these people and have no further information.There is an article on these people in the Fall 1981 issue of 'Maryland Magazine of Genealogy,' Vol. 4, No. 2 - "The Em(er)son-Cobb-Hawkins Connection by Robert Barnes:
"James Emson (Empson or Emerson) first appears in Calvert County(Maryland) in 1686 as the husband of Rebecca, widow of John Darnall.Emson was named executor and legatee in the will of William Harbutt of Calvert County dated 26 January 1699.James and Rebecca were evidently communicants of Christ Church Protestant Episcopal Parish in Calvert County in 1701, when the birth of their daughter Rebecca was recorded."
On 2 November 1703 Thomas Thurston, son of the late Col. Thomas Thurston of Baltimore County, sold 500 acres of 'Elberton' to James Empson of Calvert County,Emerson/Emson.The family may not have moved to Baltimore County immediately since his name does not appear on the Baltimore County Tax Lists for 1699 through 1706.However, James died in St. George's Protestant Episcopal Parish, Baltimore (now Harford) County, Maryland, leaving a will dated 5 January 1707/8 which was proved 26 January the same year."
"Rebecca, wife of James Em(er)son, may have married some time prior to 1686 one John Darnall of Calvert County.If so, no children of this marriage have been identified.At any rate in 1686 James Emson and wife Rebecca appear as accountants of the estate of John Darnall."
"The will of James Emson, dated 5 January 1707, proved 31 January 1707/8 in Baltimore County, named his wife Rebecca as executrix, and his children James (not yet 17) Eliza, Rebecca, and Anne.Emson's estate was administered on 9 October 1710 by the Executrix, Rebecca, 'now wife of James Cobb.'
"The children of James and Rebecca (--Darnall) Emson were: 1. James Emson, not yet 16 in 1707; Eliza Emson, birth date unknown, married first Mark Whitaker on 13 February 1717, and second on 6 October 1729, Francis Taylor, both marriages taking place in St. George's Parish, Baltimore (now Harford) County; Rebecca Emson, born 12 March 1701 in Calvert County, married in St. George's Parish, on 23 December 1718, John Hawkins, Jr.; Anne Emson, birth date unknown, married Cornelius Poulson on 23 December 1720 in St. George's Parish; Rachel Emson born 7 June 1708, in St. George's Parish, married Gregory Farmer on 14 June 1723.There does not appear to have been any children of this marriage."
There is further information on this family in this booklet.