The John Kingdon Mary Ann Lycett married in 1831 was the son of George Kingdon of Garston, Frome Sellwood, Somerset. I understand the marriage was witnessed by Benjamin Bayly Kingdon, his brother. John Kingdon was a Baptist missionary, in Jamaica (from 1832 - she accompanied him to Savannah la Mar, where Baptists were under persecution) Belize, the USA, and ultimately, under the auspices of the Baltimore, Maryland, Baptists, Liberia, where he died in 1854. Family deeds associated with Longleat suggest his death was not known to his kin in England until 1865. His sister Lucy also went to Jamaica to run a training school for teachers under anti-slavery auspices until she married William Wemyss Anderson there in 1834. Benjamin Bayly Kingdon was a C of E stipendiary Curate in St Dorothy parish in Jamaica in the late 1840s and wrote a sanitary report on the island later.
I'm sorry if I haven't picked this up, but I'd very much like to know more about Mary A Lycett - not least whether she was associated with the London anti-slavery movement, but even her address and parentage would be useful.