Could Sally = Sarah (or even Susan)?

Last night, I once again tried to do some research on finding Sophia's father. I tried to do a process of elimination, using census records and sophia's age at the time plus # of females in the household in that year, and i was able to rule out some individuals. But still no luck. I think this may be something I'm going to have to go to the library to research.

But as it always happens, everytime I search for Sophia's father, I end up searching for her mother as well. I know the name of her mother (at least i think I do!) but the search has not been made any easier b/c i have not found any marriage records.

Here's what i know:

When first searching for Sophia, i found a family tree on rootsweb that listed Sophia and Wille Daughtridge (but I think they spell it Doughterage or something like that) but i know it's them. Sophia's mother and father are listed as "Susan Land" and "Isaac Braswell".

I figure this must be true because Sophia's first born daughter was named Susan, and maybe she named her daughter after her mother?

So I go to prove this relationship, but all i find on ancestry.com is a record of Sophia's mother listed as "the daughter of Charles Land, Sr." So all that tells me is who her maternal grandpa is. No proof of her father yet except i know he's a Braswell.

Then I go search for Charles Land. All i find on ancestry.com of him is a list of his children plus "another daughter". Well as it often goes, this "another daughter" is who i need!

Then I find Charles Land's will on the genweb site. He lists his daughter as "Sally Braswell".

So is it Sally or Susan? Well, for now, I assume Sally.

And then, last night as I was researching, I found out something. Back then, Sally was often just a nickname for Sarah. As Polly often was a nickname for Mary. (I have no idea who made up these rules, must be the same person that said Bill was a nickname for William!)

So anyway, now I wonder...is my gggg grandmother "Sarah Braswell"?? And is Isaac Braswell really Sophia's father? I want to believe that but I don't want to get myself in trouble by just assuming everything I read. I've learned from mistakes and realize when you assume and don't check sources, you start climbing up the wrong tree. I just want to make sure i'm researching the correct branch.