She came from a Jewish family, and her maiden name was Krakowska. When she was four years old she moved with her family to Wuppertal in Germany. In 1932 the Krakowski family: the father, Froim and the mother, Frimeta, along with their children, Rachela, Elieser, Dawid and Fayga, the eldest, were forced to leave Germany. They fled to Belgium, and two years later they reached Brazil.
Fayga liked to draw from her early youth. During her trip by boat to Brazil she drew portraits of the passengers and crew which have survived to this day. Thanks to those drawings she acquired chocolate, which she then shared with her younger siblings. Upon their arrival to Brazil, the family settled near Rio de Janeiro in a city called Nilópolis. Fayga took on many different jobs, including as a secretary, as she spoke five foreign languages: German, French, English, Spanish and Portuguese. In 1939, she signed up for a free drawing course at the Brazilian Association of Fine Arts in Rio de Janeiro, which she attended every day after work. Two years later she got married to Heinz Ostrower, a German historian and philosopher with whom she had two children, Carl Robert (1949) and Anna Leonora (1952).
In the mid-1940s, she created a series of illustrations and book covers for a few famous Brazilian authors: Aluísio Azevedo, Graciliano Ramos and Joracy Camargo. In 1946, she completed a six-month course in graphic arts at a private institution, Getúlio Vargas Foundation, where she honed her skills in such fields of art as engraving and woodcuts. One of her lecturers was Thomas Santa Rosa, a famous scenographer, who became known for his stage design for the play The Wedding Dress by Nelson Rodriguez that was directed by a Polish director – Zbigniew Ziembiński (this show set a new direction in contemporary Brazilian theatre, which was mainly due to the Polish director). Two years later, she had her first solo exhibition at Itapetininga Gallery in São Paulo. Her style was comparable to that of German expressionism, although the subject matter of her work expressed social involvement. Often her woodcut pieces presented women washing clothes, children from the favelas of Rio de Janeiro and other scenes portraying the life of the poor. Käthe Kollwitz, a German graphic designer and sculptor, greatly influenced Ostrower’s initial stage of artistic activity.
In 1951, Fayga Ostrower acquired Brazilian citizenship and her art was exhibited in museums in Brazil and abroad more and more often. In 1955, she received a yearly scholarship from the Fullbright Foundation in New York, where she visited multiple museums and worked at the Brooklyn Museum Art School. Fayga’s works have been exhibited at The Contemporaries Gallery and she was often invited to give lectures.