I am not from Tecumseh's line, I am a decendant of his sister Tecumapease.
My information came from the genealogist we hired quite a few years ago, plus the writings of Harold Somerville. In "The History of Wood County, West Virginia,"
it states that under the "Sheppard Family" it states that "Samuel Sheppard 1803 MD - 1872 . . . In 1823 he married Amelia Full 1893 - 1876, daughter of Lewis Full, born 1765, and Jane Collins Full, born 1768, who came from Potomac Valley to settle Full's Fork in 1818. Jane was daughter of Rupert and Tecumopeas Collins, born 1749. Tecumopeas was sister of Tecumseh 1768 - 1813, and daughter of Shawnee Chief Pukeshenwa, who died at (battle of) Point Pleasant 1774, and wife, former Mary Iaac 1728 - 1823, who was kidnapped because of her red hair, at age 5. Her father, Fredericke Iaac, born in Holland 1680, died 1799 in the Potomac Valley. This goes along with the findings of our genealogist, although I have never been able to connect Rupe to Tecumapease on my own.
The information about Tecumsehs mother was found by our genealogist, and by information from the Iaac family.
From Odin, Illinois, James G. McKee writes, "Jane (Collins) Full was a niece to Tecumseh and the mother of Lewis Full's children. Uncle Joe Full never denied his Indian blood but seemed proud of it."
I also found a bit of information in the books by Allan Eckert