I noticed your query; my grandmother was Sarah Eulee Van buren she was b. Tx mid 1800's. An aunt said she was a cousin of Martin V.B. and did not like him,not sure how close of distant a cousin.I have nor benn able to connect butI copied pages from a book that is on a tape in the LDS Library, no help for me but it give quite a few of his relatives. You can order it at a family history center of the church-they will help you find it. There are published biographies of him -check libraries. Good luck that is a branch of my family that I am at a loss how to go further,My gndmother m. Abraham Fike Waldron.