Shân was born in Ffarmers, Llanwrda, West Wales and graduated from the University College of Wales, Aberystwyth. She has been a professional soloist since 1995, the year in which she won the Blue Riband at the National Eisteddfod. She is a versatile performer with an extensive repertoire and is equally at home in opera, oratorio, contemporary music and music theatre.

Her BAFTA award winning self-titled music series for Channel 4 Wales ran for two successful seasons and was nominated for the best music programme in the Montreux Festival. Other television appearances include being a soloist in 'Music Under the Stars' with Bryn Terfel and Michael Ball from the Faenol Festival, soprano soloist in Handel's Messiah with Bryn Terfel for Channel 4 Wales, soloist in Proms in the Park for BBC Wales, soloist in Royal Gala from the opening weekend of the Wales Millennium Centre on BBC 4, presenting the L'Orient Inter-Celtic Music Festival for Channel 4 Wales, and appearing as a panelist in the 'Just Up Your Street' talent show and 'The Lyrics Game' both for BBC Wales.

In 2005, Shân made her television acting debut playing the role of Davina Roberts in the highly successful drama series 'Con Passionate' for Channel 4 Wales and was nominated in the “Best Newcomer” category at the 2006 BAFTA Cymru awards. Filming on a third series of 'Con Passionate' has begun.

Shân performed the role of Carlotta in Andrew Lloyd Webber's West End production of The Phantom of the Opera for fifteen months in Her Majesty's Theatre, London. In 2006 Shân sang the role of Mary Roberts in the new Welsh musical by Mal Pope and Frank Vickery, Amazing Grace, on tour with the Wales Theatre Company.

Concert highlights include being a soloist in 'Glamorous Night' a tribute to Ivor Novello performed at the Novello Theatre, London, the Wales Millennium Centre, and in San Francisco, performing in both the opening and closing concerts of the inaugural International Festival of Music Theatre in Cardiff, a tour of Britten's Les Illuminations with the Chamber Orchestra of Wales, a St David's Day celebration concert to celebrate the life of Dylan Thomas in New York and leading the singing of the National Anthem in front of 72,000 spectators at an international football match at the Millennium Stadium. In 2005 Shân toured Wales with her critically acclaimed show 'Cothi & Cream' with the male group 'Only Men Aloud'. Shân is a frequent guest on Radio 2's 'Friday Night is Music Night' with the BBC Concert Orchestra and a popular soloist in Royal Philharmonic Orchestra's concert series 'Here Come the Classics'. In 2007, Shan made her debut as a soloist at the Welsh Proms, in a concert of film music with RPO conducted by Owain Arwel Hughes.

Her debut album Passione with the Welsh National Chamber Orchestra features international harpist Catrin Finch. A promotional video of one of the tracks was voted Most Watched Video on Classic FM television.

Shân currently hosts her own radio show for Radio Wales.