Tabbert was born as Florence Keech in Batavia, Kane County, Illinois, USA, on 25 December 1878. Her parents were Orlando Keech (1849–1928) and Josephine Anderson (1858–1928). While she was a child, the family moved to her father’s hometown, Madelia, Minnesota. As a young woman, she worked at a bank in Tyler, Minnesota. Since her parents thought she worked too far from home, she moved back to Madelia and took a job as a secretary for a lawyer.

On Christmas Day, 1912, her 34th birthday, she married Albert Tabbert. He was an agent at a railroad depot. The couple lived in several towns and cities in California and Minnesota because of his job. The couple had three children, including a daughter who died in infancy.

Her husband passed away in 1956. In 1963, she moved to Bethany Lutheran Home in La Crosse. In 1982, she moved into Bethany-Riverside when it opened. At the time of her 109th birthday, she had four grandchildren and five great-grandchildren.

Tabbert passed away in La Crosse, Wisconsin, USA, on 14 March 1990, at the age of 111 years, 79 days.