Date of Birth:

The Register of Births, Deaths & Marriages:
Births registered in July, Aug & Sept 1900 (page 77) gives:
Margaret Amelia Bryars, Lambeth District, Volume 1d, page 482.
The transcriber mentions Sep 1900, but it appears they always adopt the latest of the 3 months in the quarter. In the case of Frederick Henry Grubb, the month given is known to be wrong. September is best ignored I think as it is probably a guess, but it will be July-Sept 1900.

OBE:

WW1 (4 Aug 1914 - 11 Nov 1918)
The first Zeppelin raid on London was 31 May 1915.

Margaret was appointed as a PO "Female Learner" on 25 April 1916 (London Gazette, 2 May 1916)
& appointed/promoted to a PO Clerk on 25 July 1919 (London Gazette, 5 Aug 1919).

The OBE was established June 1917, with military and civil divisions created in Dec 1918.
OBE and other awards are announced in the London Gazette, I cannot find this one as yet.

Marriage:

The Register of Births, Deaths & Marriages:
Page 311, Marriages Registered in January, February & March 1923:
William F. Holdsworth      Bryars, Bromley District, Vol 2a, Page 911

Family:

Joseph Owen Bryars: b Jan-Mar 1902, Lambeth District, Vol 1d, Page 461.
Sister: know in the Bryars family as the queen mum because she was so like the queen mother.
Youngest Sister: Babs Welsh (Welch?)