Stefanenko was born in Yekaterinburg (then Sverdlovsk), the daughter of a Belarusian-Ukrainian nuclear engineer[2] who worked in a secret unnamed underground city, close to the Ural Mountains.

After being scouted in a restaurant by director Beppe Recchia, she made her first television appearance on the variety show La grande sfida, alongside host Gerry Scotti.

She played the character Angela Cornelio, one of the protagonists in the television series Nebbie e delitti (Fog and Crimes), which aired on Rai Due from 2005 to 2009.

She has also hosted many programmes, including the 2001 edition of Festivalbar, which is an annual series of televised summer concerts performed by both Italian and international pop groups in town squares throughout Italy; and Italia's Next Top Model in 2009.

In December 1995, Stefanenko married Italian entrepreneur and ex-model Luca Sabbioni, and they have one daughter, Sasha, who was born in 2000.