Ghadie was born in Eccles in Greater Manchester to Joseph Ghadie, a French-Lebanese shop owner, and Patsy, an English actress who met while working in Abu Dhabi, where she also lived as a child. She also has a brother named Tariq.
She made her acting debut when she was 11, appearing in a single episode of Cracker ("The Big Crunch"). She then made appearances in Children's Ward, Heartbeat, Doctors, and the children's series Life Force. Her big break came in 2000, when she beat Suzanne Shaw and Kimberley Walsh to the role of Maria Sutherland in Coronation Street, where she has been at the centre of some of the show's biggest story lines in recent years.
Ghadie was placed 53rd in the 2003 FHM's 100 Sexiest Women in the World, and voted sexiest female by the readers of Inside Soap magazine in 2005. In the same year she impersonatedHolly Valance in a celebrity version of Stars In Their Eyes – which she won. She also appeared alongside her Coronation Street castmates in a celebrity version of the TV show Family Fortunes in December 2006. In 2008 she appeared in the fourth episode of Keith Lemon's Very Brilliant World Tour, which was set in Egypt. In early September 2009 she appeared on Saturday and Sunday morning ITV kids' entertainment show Toonattik as a stand-in for regular Anna Williamson; her team lost 147–60 to Jamie Rickers and she was given the humiliating Toonattik pie in the face at the end of the show. In Autumn 2009, Ghadie took a short break from her role as Maria on Coronation Street for maternity leave. She returned to the show and resumed filming in May 2010.
In January 2013, Ghadie began appearing in the eighth series of Dancing on Ice, partnered with French ice skater Sylvain Longchambon. She sustained a concussion a few days into the pre-series training. She was eliminated in Week 8 of the competition losing out in a skate off to Luke Campbell.
Ghadie married Matthew Smith, a property developer, in St Philip's Church in Alderley Edge, Cheshire on 10 September 2005 after a seven month engagement. On 19 October 2009, she gave birth to a baby girl called Freya Her character temporarily left Coronation Street to go on maternity leave. She and her husband announced that they have separated by mutual agreement on 4 January 2011. On 4 November 2011, it was revealed that she had reverted to her maiden name of Ghadie following her decree absolute which was granted the same day.
Ghadie's father, Joseph Ghadie, died of cancer on 14 April 2009.