She was born in England and returned to Uganda shortly thereafter to be raised by her grandparents of the Omusu (edible rat) clan. While there she attended Lake Victoria Primary School, Gayaza Junior School, and Wanyange Girls School. After graduating secondary school she arrived in the United States to continue her studies. She earned an Associates degree with honours from City University of New York, a Bachelor of Arts degree from New York University, and a Master of Arts degree with Distinction in Mass Communication from the New York Institute of Technology. Sylvia went on to work as a Research Consultant at the UN headquarters in New York, the World Bank in Washington, as a proposal writer with Maximus Inc., and as an independent consultant in public relations and business development with various firms.
After living in the United States for 18 years Sylvia returned to Uganda. In 1998 she became romantically involved with longtime acquaintance Muwenda Mutebi II of Buganda. Their engagement was announced on Valentine's Day February 14, 1999. On 27 August of that year she married the King at St. Paul's Cathedral on Namirembe becoming the first queen of Buganda in 50 years. On 4 August 2004 in London, the Queen delivered her first child, Princess Katrina Sarah Ssangalyambogo which means "buffalo's horn". She is also stepmother to the King's previous three children.
As Queen, Sylvia has worked raise awareness of the value in educating girls. She endorses abstinence from premarital sex in order to avoid HIV/AIDS and has tried to reduce the stigma of those living with the disease. The Queen is a patron of various organizations and heads the Nnabagereka Development Trust Foundation. Sylvia has spearheaded immunization campaigns against measles, polio, tetanus and other diseases. She also established the Kampala Ballet and Modern Dance School, the first of its kind in Uganda.