I am trying to research my family tree. I am confused as to the parentage of my greatgrandfather.

My name is Laura Alexander Gomoll daughter of
Lee Edward Alexander (1944-) Gallipolis, Ohio & Elizabeth Ruth (Gorney) Alexander (1945-)Toledo, OH
Lee's parents are Carl Edward Alexander (1909 West Virginia - 1978 Delta, OH) & Bertha Lee (Kittle) Alexander (1918 Randolph, County West Virgiaina -2011 New Phillidelphia, Ohio)
Carl is the son of Charles Edward Alexander (1871 West Virginia- 1966 West Virginia) & Matilda May (Lambert) Alexander (1879 Ohio -1953)
I believe Charles is the son of Samuel Alexander and Sarah.

But this is where my confusion is at. My cousin is working on the tree as well. And she told me that it was Samuel and Sarah once, then another time she said it was Edward Porter Alexander and Sarah. She also had Samuel with Mary instead of Sarah. So I am very confused.

If anyone has any information, I would really appreciate it.