Answer: Depends on when you were born. It started with three but their parents kept having to add more or repurpose other rooms.
Everyone agreed there was only ever one toilet and one bath - no shower though - and that it was a source of many arguments and much door-banging during their youths.
It was a busy, noisy, happy scene as the siblings, whose ages span 25 years, hashed out their versions of the family history over drinks and entrees, ahead of a weekend of reunion activities.
It was just the seventh time the whole tribe, now aged between 56 and 80, had been in one place at one time.
The first time was in 1972, by which time the youngest, Stephen Webster, was 9. The time before this was 2015.
By the time he was born, he was already an uncle to nine nieces and nephews.
That number has since swollen, with 93 total grandchildren, great-grandchildren and great-great-grandchildren.
Add the 11 siblings, and a 12th - a sister, sadly stillborn - and the population footprint of their parents, William (Roy) Webster and Jean Lomas, reaches 105.
Some of the siblings understood their parents initially wanted three boys and three girls.
They had a girl, then two boys, then an unbroken run of seven girls - no multiple births - before Stephen came along.