Andrew Verney
From Tardis Wiki, the free Doctor Who reference
Andrew Verney was the maternal grandfather of Tegan Jovanka. He was living in the village of Little Hodcombe in England in 1984. (TV: The Awakening)
It is unknown if he was the father of Tegan's aunt Vanessa (TV: Logopolis) or the grandfather of her cousin Colin Frazer (TV: Arc of Infinity).
His daughter, Tegan's mother, was still alive in 2006. (AUDIO: The Gathering)