Let's work on this in steps.How do you know guaridanship was received.Do you have copy of old papers?What was date of guardianship, and county of residence of the guardians?If guardianship was received of Richard, what do you mean what happened to him and "other" siblings - how do you know there were other siblings.
Do you know county and state of death of Cuthbert & wife?
Francis Marion b 1861, where?
According to Everton's Handybook for Genealogists, Shelby Co, TX has marriages beginning in 1882, probably had a courthouse fire.Look at J.B. Sanders book, what dates did it cover?Does it mention a courthouse fire?Check Shelby Co, TX GenWeb site, many GenWeb counties are putting their cemeteries online, maybe Lucy's parents are buried there, and some counties are posting other records, such as marriges, on their sites.
Check Crawford Co, GA GenWeb site, see if they have posted their cemeteries online for Catherine and Walton.
I suggest in your next queries, work on smaller areas of research.It took me a while to figure out all your questions.And, how to answer so much, and at the same time try to make myself clear to you.Which Ihope I have.