Above Quilt Index information researched by the Texas project, which featured this quilt in their book Lone Stars, pages 54-55.
The maker's great-granddaughter, born Iris Mitchell, brought in the quilt for documentation and told the project that Margaret Dickerson (ca 1845-1916) stitched it in the 1860s in Missouri and brought it to Texas with her about 1875. Margaret had 4 children, the third was Gillie Dickerson Mitchell, Iris's grandmother, born in Texas in 1874. If you will recall the quilt at the L.A. County Museum of Art is attributed to Margaret and Gillie Wright. Iris noted that Margaret Dickerson's sister was also a quiltmaker named Lula Wright and a third quilt was made for a man named Van Wright who moved to California.
So we have a Margaret Wright Dickerson and her daughter Gillie Dickerson, who left a paper trail.