In looking through "History of the Families of William Osburn" I find 2 possible families that your Margaret might have come from: The following sons of William Osburn and Nancy Vaughn married and had daughters named Margaret.
Christopher Osburn settled on a farm now owned by Harry Grace, south of the village of Millbrook, in Worth township, Mercer county, Pa. He was twice married. His first wife was Nancy Coleman, of which union there were seven children-Joseph, Nathaniel, William, Ephraim and Bennett (five sons), Nancy and Elizabeth (two dqughters). His wife died and he afterward married Nancy Waldron. By this wife there were seven more children-Sarah, Mary, Hannah, Lucinda, Margaret and Jane, and one other, whose name I have lost (seven daughters).
William Osburn married Nancy Porter. They settled in Venango county, near Clintonville. Their children's names are as follows: Margaret, Hannah, Alexander, James and George, all of whom are now dead.