Elizabeth was the youngest daughter of Joel and Sarah Mackey Coffey. Joel was born Jun. 15, 1789 in TN and died Dec. 10, 1855 in Vancouver, Clark Co., WA. He married Sarah Mackey on Apr. 19, 1818 in Maury Co., TN. Sarah was born 1795 in Rutherford Co., NC, the daughter of William Lewis Mackey and Elizabeth Ashbrook.
Elizabeth was born May 8, 1836 in Booneville, Cooper Co., MO and died Apr. 12, 1905 in Portland, Multnomah Co., OR. She married Lewis Van Vleet (marriage record not found). Lewis was born Oct. 21, 1826 in New York and died Apr. 15, 1910 in Washington.
From a website owned by the Port of Camus-Washougal  I learned that "Lewis Van Vleet, who established a DLC (Donation Land Claim) in Fern Prairie, was a U.S. Deputy Surveyor and Clark County Representative in the Territorial Senate." The Lewis and Elizabeth Van Vleet home, located at 202 NE Graham St., Portland, Oregon is on the National Historic Register.
The Van Vleets had at least five children:
Lois, born Dec. 25, 1856, died May 13, 1857
Harriet Lewis, born Nov. 17, 1858, died Nov. 16, 1863
Sophia Louisa, born Oct. 30, 1862, died May 30, 1913. From the same website mentioned above, I learned that "Louisa Van Vleet Spicer Wright , was one of the first women doctors in the state of Washington. She was born in 1862 at her parents' "Oak Grove Farm" in Fern Prairie. In 1885 she graduated from medical school [at] Ann Arbor, Michigan. The land on which this park is located was given to Louisa by her father. In 1901, Louisa married James W. Wright, a widower."
Lewis, Jr., born May 18, 1875, died Aug. 30,, 1957
Felix F., born Jan. 11, 1878, died Nov. 26, 1919. From an undated paper by an unknown author I found that Felix was murdered in Newman, Stanislaus Co., CA. He apparently attempted to intervene in an argument between a friend and Ed Newson, an officer in the Newman Police Department. Newman first beat Felix then when he called for help, Newman shot Felix three times. The subsequent Coroner's inquest determined that Felix was murdered. Felix left a wife and eight children.
Lewis, Elizabeth and all of the Van Vleet children are buried in the Fern Prairie Cemetery  at Camas in Clark Co., WA.
 Fern Prairie Cemetery Burial Records, Cemetery Dist. #1, PO Box 969 Camas, WA 98604 online [http://www.rootsweb.com/~wafpc/p54.htm], accessed [downloadable pdf containing all burial records]
Thanks to Nathan Reynolds of Longview, WA for information about the Fern Prairie Cemetery website.