One thing about family history is you may have to look at the entire family to try to get hints—birth order, naming patterns, occupations, where living etc.
Children baptized at Earsdon St. Albans to Robert Mitford/Medford/Midford, Ship carpenter or shipwright in Hartley by his wife Jane
All are baptism dates, not necessarily birth dates, or burials not necessarily death dates
Barbara Metford baptized 5 Mar 1780 d/o Robert and Jane, of Hartley
John Midford baptized 27 Jan 1782 S/o Robert and Jane, Shipwright of Hartley
Burial: Hannah Mitford 22 Aug 1783, no age, d/o Robert and Jane, ship carpenter of Hartley
Robert Midford baptized 10 May 1784 s/o Robert and Jane, ship carpenter of Hartley
Hannah Mitford baptized 21 Jan 1787 d/o Robert and Jane, ship carpenter of Hartley
William Midford baptized 1 May 1791 s/o Robert and Jane. ship carpenter of Hartley
Burial: Henry Midford 1 May 1891 s/o Robert and Jane, ship carpenter of Hartley, no age given
Burial: Jane Midford 2 Mar 1793 d/o Robert and Jane, shipwright of Hartley, no age given
I looked for a burial of Robert but the writing is very tiny and it is late. I might go over it again. I do think that Jane Mitford buried 2 Mar 1815 age 63 of Hartley is your Jane Henderson. That would put her in her early 20’s getting married. I checked the burials on the date that you have and no one was buried on that date or anyone near it with the name of Jane. There is also none by that name on my transcript for 1834. The Mary Mitford, age 36 buried 6 Jul 1814 was the wife of Robert jr. Mary Boyne and Robert married in Earsdon 1 Dec 1804.
There are no further baptisms in Earsdon of anyone with the name Mitford and derivatives from 1813-1839, no other burials except Mary and Jane above.
Sorry I cannot be of more help but I am limited at what information I have.
Janis