Hello Jenn,
This the biggest problem I have come across. Positive identification without parents' names and very often the ages not consistent (the latter is the worst because a lot of these boys did not even know their DOBs).
However, with the "Marion" there is a possible solution. I have a copy of the Parkhurst Governor's Log for 1844 (no other years exist unfortunately as they were destroyed in a fire at the prison) and this does sometimes contain parents' names, for example, an unusual surname William UDLE, his Mother's name is Hannah UDLE, a Weaver living in Frome, Somerset........or John McCORMACH, his Father is Martin McCORMACH, a Shoemaker living at St Hellens Walk, Derby.
And, for any descendants of these two boys that I could contact, they possibly could be very interested in that the Log does contain a brief description of their lives up until the time they were imprisoned........of course, my major difficulty, contacting descendants. Let me know if you would like an example of these "descriptions".
For now
Tony