I don't have Lydia or John Rowland. However, I do think your guess might be reasonable.
I have John Stiffler marrying Catherine Kitzmiller 26 Sep 1823 in Washington Co (unfortunately, their marriage licenses were destroyed by a fire in the courthouse in Hagerstown abt 1890).
In the 1840 census, John Stiffler was in Sharpsburg, and had a son and four daughters (two born 1825-1830). I can not find this John Stiffler in any census 1850 or later, and do not ahve the names of any of these five children.
If you do have info on this John Stiffler, I would appreciate what you'd be willing to share.