Aeromys ...
As promised, here is a bit more background for you
You might be interested to know that your Mum would have been 1 of only 13 Female VR (Preliminary Flying Badge qualified) Cadet Pilots, out of a total of 58 VR PFB Cadet Pilots in 1953.
More information here on pages 84 & 85. It's very interesting to read about the 'politics' of the time leading up to the closure of the RFS's
RAF Reserve & Auxiliary Forces
15 RFS was part of 65 (London) Reserve Group - HQ Hendon along with 18 RFS (Fairoaks), 17 RFS (Hornchurch) and 1 RFS (Panshanger)
More follows ...