Ratio of chainring to cassette teeth for most folk on 700C on the flat is between 2:1 and 3:1 but usually at the high end. Lower climbing gears drop that. Add in that HK has done quite a few miles on a Moulton (about 2/3 the rollout of 700C), lots on a roadified MTB and a fair number on a Brompton and include racing for several years (big gears) and freewheeling downhill (which is her preference) and they all push the ratio up.