I am researching the same line.Here is a brief overview of my "somewhat" sourced notes:
Wm Brightman + Susannah Cornell c:George,Thomas,William,Walter,John,Clark, all b. Portsmouth, Newport, RI.
2. John + Elizabeth Ann Cleaver c:Robert,Susanna, Wm D.,Hugh,George, all b. Portsmouth
3. Wm D. + Mary unk.(died young) 4.George, b. LA 1831 4.Mary, b. LA 1833 4.Elizabeth, b. LA 1836 m. Stephen F. Minton
I do have pages of notes on the other descending generations children's lines, but won't include details here w/o knowing what you need. Here is my problem:I know that Wm (+Mary) are Elizabeth's parents.However, the 1850 Walker Co TX census states that Wm was born in CT in 1786, NOT in RI., which would mean that I have fallen victim to the maze created by Several Generations of this family who all named their sons Thomas, Wm, George, or John.
New England Historic & Gen. Society has some interesting entries, but I haven't untangled who belongs where.