The Rankin Murison Connection

Francis MURISON (1723-1801) married Elspet WOOD (1725-1801) and had children James (1757-1841), Ann (1760- ? ), Margaret (1755-1820), Elspet (1756- ? ) and Mary (1764-1801). Margaret married George RANKIN in 1793 and Mary married James RANKIN. Can anyone add to this?