From my notes .on the Armistead family:
I have William Robert Siegel Armistead (1862-1907) and Thomas E. Armistead (1864-1952) as the sons of George E. Armistead (1835-1911) and his first wife Rebecca B. A. Greenstreet (1842-abt1873) who he married in 1861. After Rebecca's death, George E. married Mrs. Susan Anderson Lawrence (1840- ?) in 1874. She had a son Alex R. Lawrence (1863-1936) by her prior marriage.
William Robert Siegel Armistead married Eliza Anderson (1869-1918) in 1887. They had nine children, seven of whom survived early childhood. After William's death, Eliza married in 1910 to his first cousin James Marion Armistead (1861-1939) son of Thomas Jefferson Armistead (1819-1880) and his first second wife, Elizabeth Parks. (First wife was Emily Groom/Grooms (1827-1853). James Marion Armistead had four wives in all: 1) 1888 Alice Leatha Carpenter (1892-1906), 2) 1910 Eliza Louisa Anderson Armistead, 3) 1922 Sarah E. Park (1880-1925), and 4) Dora Alice Burton Lee (1874-1939) widow of Michael L. Lee. All of James' five children were by his first wife.
They are a confusing bunch...there were at least two George E. Armisteads, one born in 1835 and one in 1858 (his nephew) so that may be where some of the conflated trees began.