I think that the "X" is actually just a poorly formed "F".
I looked at the Rocque Map for that part of Bermondsey. Although the map is a little earlier (it's dated 1746), it gives a pretty good idea of how the area would have looked when your ancestors were living there.
Snows Field and Crucifix Lane both intersect with Barnaby Street (now just part of ...
A great many records can be generated as a result of a person being accused and tried for a crime. To evaluate these records properly, it helps to find all the records you can that pertain to the crime(s) and study them as a group.
Some guides to help you get started:
Prison/Hulk/Gaol Registers (Crime & Criminals) (Including Scotland) at GenGuide.co.uk
Looking over the question and your tree on Ancestry, one fact jumped out at me. When you look at the profile of Mary's husband, the John Juden b. 1804, you have only one record type -- the marriage banns for the 15 Jan 1825 marriage of John and Mary in Thorpe, and the various Baptism/Christening records of the children which you've noted in your question.
Another collaborative genealogy website, WikiTree has a Global Cemeteries Project that aims to help people find burial places. Just sign up; no charges for using the site. To build a tree there, we must use solid sources.