Documents from early Quaker records would seem to prove Priscilla Shephard m. John Rowland and not Thomas Rowland, his brother John.
Registry of Arrivals for Bucks Co., PA
"John Rowland, wife Priscilla, brother Thomas, of Sussex."
Source: MINUTE BOOK "H" MINUTES OF PROPERTY BEGINNING 9TH DAY OF THE SECOND MONTH, 1712. THIS IS BOOK "H." IN THE SECRETARIES OFFICE. The 13th 6 mo., 1714....
"Signed a War'rt to Jeremia Langhorne for 500 a's in Right of John Rowland and Priscilla his Wife (formerly Shepherd), and of Tho. Rowland, being the Remainder of all their Three Purchases, besides an addition purchased of the Comm'rs by the s'd Jno. Rowland to make up the said 500 a's, he having sold so much more than the said Purchase; dated this day (dat. 26, 5 mo)."
Passengers on the Welcome, pg. 249.
John Rowland and Priscilla,his wife, of Billinghurst, Sussex, first purchaser.
Thomas Rowland, Billinghurst, Sussex, first purchaser.
The wording in some records may be what caused confusion for some researchers. Minute Book H- "... Signed a Patent to Charles Brockden for 500 acres in Hill Town, in Bucks County, in Right of John and Thomas Rowland and Priscilla Shepard...dated ye 9th of ye 2 mo., 1712."
Below is an example of an oft-cited source which is now thought to be in error. Why? None of the official Quaker records suggest Priscilla m. Thomas.
THE HISTORY OF BUCKS COUNTY, PENNSYLVANIA, (1682 from the discovery of the Delaware to the present time), by W. W. H. Davis, A .M., Doylestown, PA, 1876.
"Of the Welcome passengers, who settled in Bucks, we are able to name the following: THOMAS ROWLAND, of Billinghurst, in Sussex, husbandman, with his wife Priscilla".
If you have an ancestry.com subscription, you can check out the many PA sources there to decide for yourself who Priscilla married. Look for the official (Quaker) records.
I would love to share info with anyone trying to make connections between the Rowland brothers who sailed with Penn and any Rowlands in VA ca. 1740+.