born in salerno, fierro made her debut in the early 1950s in the neapolitan dialect theater, and shortly later she made her first appearances in films. in june 1954, she acted in the surreal comedy play written and directed by dario fo "i sani da legare", then, in the autumn of the same year, she entered the prestigious stage company of eduardo de filippo, with whom she achieved some large success. she was also critically appreciated for her performances in "miseria e nobiltà" by mario scarpetta and in "palummella zompa e vola" by antonio petito.