Hi christineann
Wellingborough Library yesterday, Wellingborough Museum today.
Neither Brook Farm nor its occupants appear to be mentioned in any of the local directories that I've found 1896-1964.
The local newspaper (at Museum) - Wellingborough News 17 Aug 1934 - shows death notice for Lilian Mary Austin at Great Harrowden aged 54 ... whilst this might only be a few fields away, I think it enough to imply that the family had moved from Brook Farm by this date. No death notice for Frank D Austin found 1937.
There's a very, very, outside chance the Musuem can help you. They have 3 photographs of land army girls, a group, a pair, and a single, all unidentified. Maybe they could make them available to you online or by email. Worth an ask ...
http://www.wellingboroughmuseum.co.ukMight be able to make it to Record Office tomorrow, if that helps.
Bryan.