She was born the seventh of nine children in Wau in Southern Sudan in 1977. The exact date is unknown. When she was preparing to emigrate from Sudan, her mother picked the date April 16, which occurs in the rainy season during which she was born. She says her name means "Black Spotted Cow". Alek was discovered at an outdoor market in London in 1995 in Crystal Palace, south London, by a Models 1 scout.
She first got attention with the help of the music video for GoldenEye by Tina Turner, in 1995 and from there made it into the world of fashion as one of its top models. She was signed to Ford Models in 1996 and was also seen in the "Got ‘Til It’s Gone" music video by Janet Jackson that year. She was named "Model of the Year" in 1997 by MTV.