Lizzy - ignore that last bit - I think I've worked it out for myself.
Births Sep 1906 - Pratt Beatrce Gladys - Tonbridge 2a 867
(That spelling mistake made it harder to find for a moment)
Tonbridge Registration district included Tunbridge Wells in 1906 (in fact until 1979)
Interestingly, the same reference includes:
Pratt John Henry Tonbridge 2a 867
Could be a coincidence, a cousin or perhaps a twin?
From this reference you can get her birth certificate, which will give you her parents details. You'll need that to go further, as there are quite a few Pratt marriages in the same district in the 5 or so years before 1916.
All sourced from (
www.freebmd.org.uk)