Below this is the lineage of the family into which Albenah Ross married, put in chronological order. Albenah's record seems out of synch with the Jolliffe text, as the only references in the cited work do not give a date of birth for her, and, the (unsourced) date of birth seems improbable:
Generation 1: Evan Thomas of Swansea (1580-1650)
Generation 2: Philip Thomas of Bristol England (d. 1675) = Sarah Harrison (d. 1687)
Generation 3: Samuel Thomas of Anne Arundel Co (b. 1655-1743) = Mary Hutchins (m. 15 May 1688; daughter of Francis Hutchins of Calvert Co, MD)
Generation 4: Evan Thomas Sr = Catherine Katherine (m. 15 jun 1730)
Generation 5: Evan Thomas Jr 1706-1758 = Albenah Ross ("m. before 1741")
So we do not have any precise dates for Evan Thomas Sr, except that he likely was born Aft. 15 May 1688, and died after 1706. Next, we can look to see what we know about Albenah's parents and her children with Evan Thomas Jr to see if any rough dates can be developed for her, but clearly, the existing birth date is incorrect.
In fact, if the parentage of Mary Thomas-Hiatt is correct, the marriage between Evan Thomas Jr and Albenah Ross would likely have been by 1723, instead of merely "before 1741."
It would be worth checking the Jolliffe work to see if any definitive dates on her parents exist; i.e., if one of them died circa 1706 (also, the supposed birth date of her husband), that would firm up a birth date for her. If death dates of her parents are both unknown, then after 1706 would be the most probably "after" this date for her birth date.