She married John Henry Carter 1 Jan 1872 in the Circuit Court at Spencer, Clay, Iowa. Anstis and John Carter had eleven children: Mary E., Charles Marvin, John H., Alice C., Marcus W., Richard Elmer, Will Reginald, Leonard Ackley, Jeanie, Russell, Harvey Carter.

From the "Spencer Daily Reporter", Spencer, Iowa, February 10, 1937,
Mrs. John Carter, Dickens Pioneer, Succumbs Monday.
"(Special in Daily Reporter)"
"Dickens--Mrs. John Carter, 83, (above), pioneer of Clay county and the eldest resident of Dickens, died Monday moning, Feb. 8, at the home of her son, Leonard Carter, ... her death.
Better known as Grandma Carter by young and old alike, her death takes one of the last of the early day residents of Dickens.
Funeral services will be conducted Thursday afternoon at 2 o'clock from the Congregational church here. A prayer service will be held at the Leonard Carter home at 1:30 o'clock. Burial will be made in Riverside cemetery at Spencer. Rev. Harold Dayton of the Methodist church will officiate.
Born in Indiana
Born in LaPorte, Ind., May 31, 1853, Mrs. Carter came to Clay county with her parents, Mr. and Mrs. Harvey Hubbard, in 1869 or 1870. The family homesteaded on a farm near Dickens which is now occupied by the Chris Christenson family.
In the early days, Mrs. Carter taught school in a sod school house near Lost Island Lake. She attended the first county teachers' institute held in Spencer.
She was married to John Carter at Dickens Jan. 1, 1872. Mr. Carter died in 1916 and since that time the deceased had resided with her son, Leonard.
Survivors
Surviving are the following children: Mrs. E. E. Bird of Leonard, N. D., Mrs. Frank Smith and Will Carter of Mohall, N. D., John Carter of Owen, Wis., and Charles, Richard and Leonard Carter of Dickens. There are 24 surviving great grandchildren. Three children preceded their mother in death, Mark Carter in 1913 and Jeanie, Russell and Harvey during infancy.
Two brother, Charles Hubbard of Rockford, Iowa, and Norm Hubbard of Milaca, Minn., and one sister, Mrs. Harry Fuller of Walla Walla, Wash., also survive.
After their marriage, Mr. and Mrs. Carter lived on a farm near Dickens. Later they moved to North Dakota, where they lived 11 years, before returning to Dickens. Previous to his death, Mr. Carter operated a meat market at Ruthven for two years.
Mrs. Carter was a charter member of the Dickens Rebekah lodge and a member of the Congregational church. At one time she served as president of the Ladies Aid Society of the church."

(Thanks to Ann Bowler for this obituary)