Howling:How did the Doctor have a granddaughter without a social life?

In 'A Christmas Carol' the Doctor claims to have built the sonic screwdriver in his room instead of looking for romance (he also mentions making a screwdriver 'a little more sonic' in The Empty Child/The Doctor Dances). How, then, could he have a granddaughter by 236 (extremely young for a chronarch)? (In anticipation of canonical argument, assume that Lady Larn really was his granddaughter who somehow ended up with the rebels.)--FredBloggs5100 aka your master ☎  04:35, February 1, 2016 (UTC)
 * The Doctor lies. Or Time Lords reproduce in a different manner. Or - there could be another explanation that someone else will come up with. -- Beardouk ☎  23:10, May 29, 2016 (UTC)