She was born in Ponce, a member of a rich family (the Ferré family fortune is estimated at 193 million dollars nowadays). However, she was inclined towards becoming a Christian servant, and chose to represent God among the people of the Earth instead. So she joined the Orden De Las Siervas Misioneras De La Santisima Trinidad (Order Of The Missionary Women Of The Holiest Trinity) in 1935.
An excellent student, Ferré graduated various universities in the United States, with grades in sociology and arts among other things. She travelled back and forth between Puerto Rico and the Eastern Coast of the states, and she absolutely loved trying to help the poor who lived in the Eastern coast.
After a stint as a member of New York's committee against poverty, to which she was named by then mayor John Lindsay, she decided in 1969 to set her permanent residence in Ponce, specifically in the poor sector of La Playa, where she became a very well liked figure.
Ferré's efforts in La Playa were written about many different times, in Puerto Rican books and newspapers, as well as in books from other Latin American countries like Venezuela.
She was responsible for opening a small hospital and a school named Centro De Orientacion De La Playa (La Playa Orientation Center) in the area. It was her dream to see that the people of La Playa improved their social and economical status by studying and getting jobs, while living in a community with adequate services.
She earned many honorary doctorates from different educational institutes, and her effort was recognized by President Bill Clinton, who greeted her personally at a ceremony at the White House.
Sor Isolina died at age 85 in Ponce, after more than half a century of public service.