Hi,
The Shenley Parish Records include the following baptisms for children of John and Ann TULL - 25Dec1783 William John - 14Feb1785 John - 26Apr1786 Ann - 28Oct1787 Susannah - 22Sep1790 Maria. I also found a burial 24Sep1781 for Susannah wife of John TULL. There is no trace of the 1792 marriage in the Hertfordshire Marriage Index.
The Marriage of Lucy SALMON at Shenley on 18Jul1819 to John OSBORNE of Wooburn in the county of Bedford was witnessed by R Salmon, Edwd Jefferson, S.Freeman, and Jane Osborne.
Hope this helps.
Regards ... Peter