Mary Elizabeth Simpson married Thomas Osborn on 03 Aug 1751 in Baltimore County, Maryland. Mary Ann Osborn was born 25 Jun 1754 in Maryland, making her the daughter of Mary Simpson and Thomas Osborn, and she married Jacob Johan Hackleman in Maryland on 20 Sep 1773. The confusion in the minds of the "co-managers" here seems to have come from the fact that at some point Mary Elizabeth Simpson was also married to Jesse Davis Oldham, presumably before her marriage to Thomas. (She died around 1798, and I have no record of a divorce from Thomas. Presumably she married Jesse first, but clearly Mary Ann was born AFTER the Osborn marriage.)
Among other sources: the book HACKLEMANS IN AMERICA 1749-1988.
