De volgende tekst heb ik gevonden op https://www.findagrave.com/memorial/124567963/johanna-koster (nog geen antwoord op uw vraag) Daar staat een overlijdensdatum van Johanna Koster (dec. 1923) dan u noemt, maar het lijkt om een tikfout te gaan, gezien de tekst bovenaan de pagina. Het lijkt me wel over dezelfde Johanna te gaan.
According to a handwritten transcription in August 1873 of marriages in Grand Rapids Janna Iot (!?) married on 4 March 1872 in Grand Rapids, Kent County, Michigan at the age of 21 years to the five years older Jan Koster, who was then also residing at Grand Rapids. Witness was Iep Koster, residing at Grand Rapids too. Jan Koster was born on 16 January 1846 in the country village of Staphorst in the northwestern part of the Dutch eastern province Overijssel, son of the then 26 years aged carpenter Thijs Koster and farmer Jantje Slager.
On 1 August 1877 their daughter Gertrude Koster was born in Oakland County, just northwest of Detroit, in the eastern part of Michigan. She died on 24 October 1926 in Grand Rapids, Kent County, Michigan, married to Peter Van Til. On 6 October 1884 their son Henry Koster was born in Grand Rapids, Kent County, in the western part of Michigan.
In June 1900 Jannie Koster (50 y, born in August 1850 in Holland, immigrated in 1873), her husband John Koster (54, January 1846, Holland, immigrated in 1869, wood carver) and their son Henry (16, October 1884, Michigan, farm laborer) lived at an own farm in Grandville village, Wyoming Township, Kent County, in the western part of Michigan. Jannie was then mother of four children, of whom two had died meanwhile.
Her husband John Koster was killed in June 1906 at the age of 51 years in a traffic accident in Grand Rapids. Cause of death: fracture of the skull. He was a machine hand then.
In 1920 Johanna Koster (69, widow) and her son Henry Koster (35, Michigan, single) lived at an own home in ward 3 of Grand Rapids, Kent County, Michigan.
In December 1923 widow Johanna Koster died at the age of 76 years in Grand Rapids and was buried on 17 December 1923 in Block N, Lot 59, Space 11 in Oak Hill Cemetery in Grand Rapids, Michigan, a few graves away from her husband John Koster, who is buried in Lot 54, Space 15. Apparently when John died in 1906, the two adjoining graves were not purchased, because other persons are buried next to him.
In April 2014 FAG photo volunteer Jay Kruizenga found her plot, space 11, where Johanna was buried, but her grave had no headstone.