The first of nine children, Morosini grew up in a small village near the mountains in very difficult time during World War II. She soon became a member of Catholic Action.
Pierina became a seamstress, like many other young women of Fiobbio, in a textile plant in Albino. She left her village only once in her life, to attend the beatification of Santa Maria Goretti in Vatican City.
On 4 April 1957, 26-year-old Pierina was walking home and a man came up to her. He made lewd comments to her and tried to rape her. Pierina attempted to defend herself and she was beaten to death by him with stones.