Her career began in 2000 when she was 18. Her first film was Real Sex Magazine. As the scene involved anal sex she had to perform her first enema, and she was also required to urinate on her co-star. One of her early films featured Sinclair in a rough group sex scene with twelve men, staged in a prison. In this scene she was choked, slapped and verbally abused and often appeared to be on the verge of tears. She has since appeared in over 300 adult films, including titles such as Service Animals 6 & 7, She-Male Domination Nation, Bella Loves Jenna, Back 2 Evil, Weapons of Ass Destruction, and Fashionistas Safado: The Challenge. In 2002 she featured in the multi award-winning BDSM themed Fashionistas; its Director John Stagliano described her as "a woman with the most incredible sexual abilities I’ve ever seen." As well as Stagliano she has often been directed by Nacho Vidal, Jules Jordan and Rocco Siffredi. In 2003 she signed a contract with Sineplex, for whom she also directed.