Krol-Benedictus was born in Achtkarspelen, Friesland, to a Frisian speaking family.[1] She received her degree in agricultural economics from Wageningen University and Research. She then studied at the University of Iowa in the United States for two years.[2] Krol returned to the Netherlands, where she took a position as a policy officer at the Stichting Fryske Kultuerried [nl] (Frisian Cultural Council) in Leeuwarden, a now defunct foundation for the promotion of Frisian culture.
She then married Gerrit Krol, a geologist with whom she had two sons, Durk (born in Brazil) and Doutsen.[1] The couple moved to Brazil and South Africa, where she worked as a research assistant at the University of Pretoria,[2] before returning to the Netherlands in the early 1970s.[1] They settled in a farmhouse in Boornbergum.[1]
In the 1974 Dutch municipal elections, Krol-Benedictus was elected to the Smallingerland municipal counsil, becoming the first elected official from the Frisian National Party (FNP) in he history of Smallingerland.[1] She served on Smallingerland's council for nine years.[1]
In 1978, Krol-Benedictus was elected to the Provincial Council of Friesland a member of the FNP, alongside FNP leader Jan Bearn Singelsma, the leader of the FNP on the council since 1966. Once Singelsma stepped down as leader in 1980, Krol-Benedictus became the new leader of the FNP in the Friesland Provincial Council.[1] She remained in office until her retirement in 1995.[1] During her time in office, Krol-Benedictus campaigned for the equality and usage of the Frisian language alongside Dutch, spatial planning, and the preservation of village and rural life in Friesland.[1] Under Krol-Benedictus, the FNP advocated for the establishment of regional Frisian language television stations in the province.[1] She was also a member of the Dutch advisory committee for the 1992 European Charter for Regional or Minority Language.[2]
After leaving office, she became chairwoman of the Feriening Lytse Doarpen [fy], where she worked to protect and preserve small Frisian villages and rural communities and led it until 2002.[1][2] In 2006, Feriening Lytse Doarpen merged with a second organization to establish Doarpswurk [fy] to support community development, village associations and cultural organizations in Friesland.[1] In 2001, she participated in a discussion with Willem-Alexander of the Netherlands and Máxima Zorreguieta on potential solutions to population decline in rural villages in Friesland.[2]
In 1997, Krol-Benedictus and Jaap Rinzema became the first foreigners to be awarded the medal of honor from the Kashubian-Pomeranian Association for their work on behalf of the Kashubians ethnic minority in northern Poland.[2] Krol-Benedictus received the award during the commemoration ceremony for the 1000th anniversary of the city of Gdansk.[2]
A resident of Boornbergum, she remained active in politics and Frisian cultural advocacy into her 90s.[2]
Krol-Benedictus died in Drachten on 25 December 2025 at the age of 94.[1] Her husband, Gerrit Krol, died in 2015.[2]