In 1997, Sienna got married to Nick Moran. Nick Moran is also an actor, director and producer from United Kingdom. But this married life lasted for only three years as they got divorced in 2000.
Few months later after Sienna got divorced with her first husband, she began dating Enzo Cilenti. Enzo who is also an actor is known for his role in the movies like The Theory of Everything, Guardians of the Galaxy, and many more. After being in love for about two years they got married in 2002. As a married couple, they have been parents twice.
In 1993, Sienna joined Gresham's School. There she was not only active in her studies but also in acting. She also appeared in several school productions. She also made her acting debut in 1993 starring the role of Fenella Maxwell in the TV series, Riders. Two years later, she also appeared in the TV miniseries, The Buccaneers. She made her feature film debut in 1996 by starring the role of Blue in the movie, The Future Lasts a Long Time. Her breakthrough role came in 2003 when she began appearing in the TV series, Helen. Her net worth is said to be around $5 Million.