Embarassingly, I keep a Google spreadsheet to track the
family bike fleet!
The OP has just prompted me to assign a 'registered keeper' to each one in the spreadsheet, much like DVLA. In reality we all mix-and-match, so we'll all have a suitable bike for the occasion, including the kids' other halves. The default setting for keeper is 'me', which I guess is fair enough but does explain the results below. Fortunately, we're all pretty much within the range of adjustment of the bikes - though our son is now over 6ft, we haven't marked the kitchen wall for about 6 years / 4" so we're officially still the same height!
Me: 14 (road, gravel, mountain, vintage, Brommie)
Mrs Spesh: 4 (road, hybrid, vintage, Brommie)
20 y/o Jr Spesh: 2 (vintage, Brommie)
15 y/o Speshette: 4 (gravel, vintage, mountain, Brommie)
Guests / Other halves: 4 ((vintage, Brommie)x2)
Average age across all the bikes: 24 (1996)
Oldest: 1938
Newest: 2020
Favourite to ride: Bianchi Specialissima X4 1987 - just an absolute pleasure to ride
One to grab if the store was on fire: Bianchi Folgorissima 1952