According to Winifred Lovering Holman's book DESCENDANTS OF ANDREW EVEREST OF YORK, MAINE (1955), pp. 257, 324, Anna M. Vickery m. Groton, South Dakota 22 Feb. 1887, as his second wife, William H. Everest, b. Royal Oak, Mich. 9 April 1844, d. Crystal, Mich. 16 Nov. 1928, son of William S. and Eliza (Baldin or Baldwin) Everest, and widower of Cornelia M. Smith. Anna's parents are given as Gilbert S. and Jane (----) Vickery.
Anna was 62 in 1923, placing her birth as ca. 1861, and no birthplace is given since the 1900 census (the first extant one which would list her as the wife of W.H. Everest) had not been released in 1955.
The one child of William H. and Anna M. (Vickery) Everest listed in this work is:
"CHARLES [EVEREST], b. 15 Feb. 1889, Groton, S.Dak. Ms. [material now at NEHGS, Boston; unlikely to contain more info] gives birth as 1887 [sic]. He is also called 'Charley' in the old charts. His father's pension rec. shows him to be living at 415 N. State Rd., Belding, Mich., 1926. Perhaps had son LAVERNE, who res. 1954, Greenville, Mich. Queries to latter not answered."
The entry on pp. 324-25 also contains this Civil War pension abstract: Declaration for Increase of Pension, 28 March 1891, Brown Co., South Dakota: William H. Everest, ae. 47, declared that he was a pensioner enrolled at $8.00 per month, that his PO address is Groton, said co. and state; that he was born, 9 April 1844, at Royal Oak, Mich., enlisted in Hubbardston, Mich., drafted at Ithaca; his wife's maiden name was Annie Vickery; they were married, by R.C. Walton, in Groton, Territory of South Dakota; the official record in co. clerk's office in Aberdeen, South Dakota. That his first wife was Cornelia M. Smith, whom he married in the fall of 1854, and that she died, 31 March 1883, Carson City, Mich. By this first marriage he had: Marie C., b. 21 Oct. 1866, Bloomer, Montcalm Co., Mich. [she = Adelbert Harnois]; Edward D., b. 13 June 1868, same [d. 27 Jan. 1869]; Edith E., b. 10 Feb. 1872, New Haven, Gratiot Co., Mich.; "Jackson L." [actually Judson L.], b. 4 Oct. 1874, same; Charles W[illiam], b. 23 Oct. 1882 [d. 31 March 1883]. By his 'present' wife, he had "Charley," b. 15 Feb. 1889, South Dakota."
So there you have it. Nothing more on Anna Vickery, who appears to be the only Everest spouse of this surname.
Hope this helps. Best wishes, Julie