In her youth, Geraldine taught a Bible class for "factory-girls" in Bromley-by-Bow in the East End of London where they lived. She attended meetings at "Berger Hall" named after William Thomas Berger.

She left London for China as a second-class passenger on the P&O vessel "Kaisar-i-Hind I" in January, 1888, age 22. The Hundred missionaries had all sailed to China the previous year. Amongst the 25 passengers (16 men, 5 ladies [sic]) aboard the steam ship with her were Miss Mary Reed (daughter of Mrs Henry Reed and sister of Mrs Harry Guinness), Mr & Mrs Hunt (travelling to Hanchung) and the Pigott family of The Sheo Yang Mission (who were eventually killed during the Boxer Rebellion).

As recorded in "In the Far East" the Kaisar-i-Hind took a route passing Gibraltar (10:30pm, 31 January 1888), calling at Naples and then passing the Straits of Messina; stopping for a day at Aden and then onward to Colombo, Ceylon.

At Colombo the missionary party boarded the P&O vessel "S.S. Deccan", bound for Shanghai. A stop in Penang, Malaysia allowed Geraldine a first contact with many Chinese who came on board. Then a stop at Singapore followed. Her first time on Chinese soil was later at a stop at Hong Kong where she was received by Dr & Mrs Chalmers of the London Missionary Society who introduced them also to Mr & Mrs Bender of the Basle Mission. Shanghai was reached next. But Shanghai was not their final destination. Staying only long enough to exchange their European clothes for the national Chinese costume, the missionaries started on again, leaving this first station of the China Inland Mission behind them and travelling on the boat Fuh-ho("Happy Harmony") in the substantially cheaper Chinese accommodations up the Yang-tsi River to Chinkiang . Lastly on to a barge some 6 hours to Yang-chau, finally arriving at Yang-chau on 23 March 1888.

She wrote to her sister after a short time in China:

After training in China, Geraldine was eventually stationed in Honan Province.

Geraldine Taylor's books have inspired generations of young missionaries such as Jim and Elizabeth Elliot to engage in overseas work. However, her writings have received some criticism for omitting some less favorable details of her subjects, specifically regarding the life of Hudson Taylor. Historians Ruth Tucker and John Pollock have noted with dismay the lack of detail given to Taylor's humanity and personal relationships. Writer Alvyn Austin bluntly accuses her of a "conspiracy of silence" about the workings of the mission. Alfred James Broomhall's perspective as the definitive historian of the CIM is more sympathetic, as he cites the need for prudence and tact that often motivated Geraldine's editorial decisions.

Her niece, Joy Guinness, wrote her biography entitled Mrs. Howard Taylor: Her Web of Time, published by the China Inland Mission.

Further reading

• Historical Bibliography of the China Inland Mission