Your find with D Allen (later Mts Harding) led me on one wild ride Jimbo!
After a good deal of dectective work I found out the following:
ALLEN, AGNES (Agnes Dorothy Allen)
Born 02 December 1886 in Auton, Middlesex.
Died September 1976 at Chichester.
Married (1) Reginald William Fowler Harding (1887-1917) on 23 February 1913 in Ealing.
Married (2) Captian Patrick Hill Normand (died 27 March 1943) Between July 1920 and 1926
Called “a spinster of the parish” in her wedding bann of 1913, she had played Wimbledon in 1912 as Miss Allen.
Played Wimbledon 3 times (1912, 1914, and 1920), compiling a 3-4 record. In 1914 and 1920 she made the 3R as Mrs RWF Harding.
Captain Reginald William Fowler Harding, London Regiment,was the third son of Mr. & Mrs. Richmond Harding of Cranmore, Isleworth. He was born in 1887 and educated at St. Pauls, where he developed a very great athletic ability. He represented his School at Cricket and Football and was the champion fives player.
In 1910 he became a member of the Stock Exchange. It was then that he became a first class Lawn Tennis player. He was the champion of the Chiswick Park Lawn Tennis Club and played in many open tournaments. In 1914 he was playing splendidly and reached the final for the plate at Wimbledon.
He was given a commission in the 18th Battalion, London Regiment (London Irish Rifles) in August 1914, and was promoted to Captain in May of the next year. Reginald served in France, Salonica, Egypt and Palestine.He was mortally wounded at Tel el Sheria (now Israel) on the morning of the 7 November 1917.
Her second husband was a Scotsman. A brief bio of her first husband calls her Agnes Dorothy Norman “of Johannesburg.” Mr Normand (the earlier reference omitted the “d”) was a Captain and a noted cricket player. There are numerous ship passenger lists with Mrs Normand, ranging from South Africa to England and even as far as Burma. The family eventually returned to the United Kingdom. As yet there is no indication of Dorothy playing tennis after after 1920. She had a son named PI Normand who was born circa 1927.
Blast bio at: Biographies of Female Tennis Players