A couple of comments came in following the post on updates to the Women’s Land Army Index Cards.
A note on the Ancestry collection is that images and indexes are excluded for individuals born less than 100 years ago. December 1922 is the latest birth date posted by Ancestry, 16,356 were born that year, up from 13,461 born in 1921 and 10,961 in 1920. That could well be why you’re not finding a card for a person who was involved. Patience.
Another comment was about a WW2 woman ambulence driver in London. Steve mentioned his mother was in uniform and therefore part of an organization. The first step is to identify the organization from the uniform in a photo, if he has one. A web search finds several articles on women ambulance drivers in WW2 England.