I have two Thompson women trying to match with families in about same area and time period. My gg-grandmother was Jane Thompson McGuire, born 1828 Allegheny County, Pa. ; don't know parents. She married Jacob McGuire of Derry, Westmoreland co., in 1846 and lived there until her most of husband's family moved to Illinois in 1859. Also have Sarah Thompson McGuire, b. 1842 also in Allegheny Co., married to Daniel McGuire, Jacob's brother . However, Sarah arrived in Illinois in 1861 & married Daniel in 1862. Do not know if Sarah and Jane were related but likely. Sarah had brother Robert Thompson whose wife's name was Elizabeth. Sarah's death certificate gave father's name as William Thompson and mother's last name was Weaver. There is story about a fire in which parents were killed and children separated. Where or when don't know. The McGuires came to Derry late 1780s; there are Cannons living in proximity to them in 1850 Derry census.