Two Stevens women married two Shipley brothers. Susanna, who married Richard Shipley, is said to be the daughter of Benjamin Stevens.  Elizabeth, who married Richard's brother Robert, was the daughter of Charles Stevens. 
However, Benjamin Stevens appears to be based in St. Mary's County, Maryland, as does his daughter Susanna. Ongoing research is therefore important to confirm that there are two Susannas rather than one, and to establish whether the one Benjamin Stevens is actually two.
Benjamin Stephens was born before 1695 in St. Mary's County, Maryland.
Father: William Stephens b: BEF 1629
Marriage 1 Lettice MNU Stephens b: BEF 1699 Married: BEF 1715 in St. Mary's County, Maryland
1717 Stephens, Benjamin Trumania Rent Rolls St. Clements
Major Truman Greenfield 11.714 SM £534.5.7 Oct 7 1726 Nov 29 1726 Appraisers: John Carebright, Laurence Lant. Creditors: Benjamin Stevens, John Cartwright. Next of kin: T. T. Greenfield (brother), James Greenfield (brother). Administratrix: Mrs. Elisabeth Greenfield.
1728 Stephens, Benjamin Stevens Chance 46 Rent Rolls
Samuel Williamson 10.469 A SM £396.6.2 £34.7.1 Oct 13 1730 A second inventory is cited in the amount of £1.10.0. Received from: Thomas Hunt, Philip Briscoe, Capt. George Clark, Thomas Swann, James Swann, Benjamin Stevens. Payments to: Capt. George Clarke, John Hale, Philip Briscoe, Benjamin Wood, John Briscoe, Rev. John Donaldson, Thomas Taylor, John Ford, Administratrix: Judith Williamson
He died 28 MAY 1733 in St. Mary's County, Maryland - Probate. 
Stevens, Benjamin, St. Mary's Co.,2nd Jan., 1732-3; 28th May, 1733.
Benjamin Stevens 17.330 SM £52.7.8 Jun 12 1733 Aug 8 1733 Appraisers: James Wood, Isaac Shemwell. Creditors: Joseph Edwards, Luke Barber. Next of kin: Benjamin Stevens, William Lock. Administratrix/Executrix: Lettice Stevens
Benjamin Stevens 12.528 A SM £52.7.8 £9.18.2 Aug 24 1734 Sureties: William Locke, Benjamin Stevens. Payments to: John Chesley, James Black, Capt. John Hicks, Charles Calvert, Henry Gibbings, Joseph Edwards, Luke Barber, Susannah Wilson. Executrix: Lettice Stevens.
1737 Stephens, Benjamin Stevens Chance 46 Patent Record EI 2, p. 622
Trumania 1750 Shemwell, Isaac 50 Patent Records St. Clements
Trumania 1750 Stephens, Joseph 50 Patent Records St. Clements
Trumania 1753 Shemwell, Isaac 50 SMC Debt Books St. Clements
Trumania 1753 Stephens, Joseph 50 SMC Debt Books St. Clements
Trumania 1756 Stephens, Joseph 50 SMC Debt Books St. Clements
Trumania 1784 Stephens, John Will of John Stephen JJ#1 f283 5/1784; 8/11/1784 St. Clements
Trumania 1784 Shemwell , James Will of John Stephen JJ#1 f283 5/1784; 8/11/1784 St. Clements
Trumania 1784 Stephens , Thomas Reeder Will of John Stephen JJ#1 f283 5/1784; 8/11/1784 St. Clements
LAND OFFICE (Patents) PT #1, Isaac Shamwell, 13 October 1744, John Higges, October 12, 1744. PP. 257-259. [MdHR17,396,1/230230. 09/08/86. Tracking No.: 10308. PD No.: 87 0385.
LAND OFFICE (Patents) LG #E, Isaac Shemwell. 13 October 1744. P. 710. [MdHR17,395-21/23/02. 09/08/86. Tracking No.: 10308. PD No.: 87 0385.
LAND OFFICE (Rent Rolls) 7 & 8, "Trumania". PP. 68a only. 4 April 1711. [1-24-1-2]. 09/08/86. Tracking No.: 10308. PD No.: 87 0385.
Trumania 1711 Greenfield, Thomas Truman 184 Rent Rolls St. Clements
Trumania 1713 Queen, Samuel 184 Rent Rolls St. Clements
Trumania 1713 Greenfield, Thomas Truman Rent Rolls St. Clements
Trumania 1713 Shemwell, Isaac Rent Rolls St. Clements
Trumania 1717 Greenfield, Thomas Truman Rent Rolls St. Clements
Trumania 1717 Stephens, Benjamin Rent Rolls St. Clements
Children of Benjamin and Lettice:
Children of Benjamin and Lettice Stevens
Named in 1733 Will of Benjamin.
Was she a Shemwell?
The Will of Richard Shipley, planter, Baltimore Co.,was made 5th Oct., 1724 and proved 24th Aug., 1725. It's provisions included:
What is the relationship of Susannah and Benjamin?
"John Stephens and Sarah parents of Charles Stephens son b. 2 Mar 1712; Susanna Stephens dau b. 18 Sep 1708; Comfort Stephens, dau, b. 8 Mar 1713.
John Stephens and Sarah Brown m 19 Feb 1704. 
Thomas Brown and Elizabeth Stephens (widow) m 13 Feb 1704. 
Robert SHIPLEY (ca. 1676 - will pr. 9 Mar. 1763) m. by 1710, Elizabeth STEVENS, dau/o Charles of Dorchester Co. [Ref. Indenture of Wm. STEVENS, 12 Oct. 1710. Has anyone found that indenture, or anything proving Elizabeth was dau/o Charles STEVENS?]
The children of Robert (son of Adam 1) are proven because they are all listed together in church records. However, the next Robert SHIPLEY, son of Robert & Elizabeth, b. 1713, m. before 1737, Sarah [DORSEY?] The book then lists the first child as Rachel, b. 1745, and the last, Lucy, b. 1765. The marriage year sounds reasonable, and so does the order of birth you listed for them. Have you found more records for those children?
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