Banotti was born in Malahide, Dublin, in 1939 to Jim and Kitty O'Mahony.[1] She was a sister of the former Minister Nora Owen and her mother was a niece of the Irish political leader Michael Collins. Living on Seafield Road, Clontarf, she attended a private primary school run by the Misses Walsh, and then the local Holy Faith Secondary School, Clontarf.[2]
Banotti was divorced for many years from her Italian husband.
Between 1980 and 1984, she presented a weekly programme on social welfare rights and information on RTÉ television. Banotti unsuccessfully contested the 1983 Seanad election and the Dublin Central by-election the same year.[4]