Williams-Stewart was born in Takoma Park, Maryland and raised in Ellicott, Maryland. Her mother was a speed-skater and was a five-time competitor at the United States. Speedskating Championships and won a medal at the North American Speedskating Championships.
Skating on the junior level, she finished 13th at the 2003 United States. Figure Skating Championships.
She began representing Puerto Rico in the 2008-2009 season. She is the 2009 Puerto Rican silver medalist. Williams-Stewart first qualified for the United States. Figure Skating Championships in the 2002-2003 season.
In the 2004-2005 season, she qualified for the 2005 United States. Figure Skating Championships on the senior level and placed 10th.
Because of that placement, she was given a Junior Grand Prix assignment the following season. In the 2005-2006 season, Williams-Stewart competed at the 2005–2006 International Skating Union Junior Grand Prix event in Andorra and finished 5th.
At the 2006 United States. Figure Skating Championships, she repeated her 10th-place finish from the previous year. In the 2006-2007 season, having aged out of Juniors, Williams-Stewart was no longer eligible to compete on the Junior Grand Prix.
At the 2007 United States. Figure Skating Championships, she placed 13th.
In the 2007-2008 season, Williams-Stewart was assigned to another senior international competition, the Nebelhorn Trophy. At the 2008 United States. Figure Skating Championships, Williams-Stewart repeated her 13th-place finish of the previous year. Following the 2007-2008 season, Williams-Stewart switched to compete representing Puerto Rico.
She was released by the United States. Figure Skating Association in the summer of 2008 and began representing Puerto Rico in club competitions over the summer.
She was sent to the Ondrej Nepela Memorial, a senior international competition, and won the event ahead of former European Champion Júlia Sebestyén. There, she won the silver medal behind reigning European Champion Carolina Kostner and ahead of Finnish skater Laura Lepistö, who would go on to win the bronze medal at the 2008 European Championships.
