I've never proven any children of Streshley Allen b. 1754.In fact, Polly Watts may be the wife of Streshley Allen b. 1785 rather than Streshley Allen b. 1754.
While you're looking for Strashley, also look for Thrashley or Thrasley.
E.g., the 1820 Boone Co., KY lists a Thrashley Allen.
As best I can figure, only Thomas and Streshley of Erasmus Withers Allen's sons moved to Ky.BUT, Erasmus had a number of brothers and cousins who could have moved to KY, hence the plethora of Allens from VA and NC.
You might want to look for related families such as the Waggeners.Related families can help tie people to particular lines.
So far as I know, we don't know the parents of Sarah Streshley.There are some candidates, notably William Streshley, but nothing proven.I'm surpriesed that there isn't a Streshley GenForum.