Sia graduated from RADA in 2006.

Since graduating from RADA in 2006, Sia's television credits include: Francis in Wuthering Heights (ITV); Holby (BBC); Scarlett in Skins (Company Prod Ltd); and The Bill (Talkback Thames). She was also in the film Wild Target directed by Jonathan Lynn for Magiclight Pictures.

Whilst training: When We Are Married; The Merchant of Venice; The Great Theatre of The World; The Last Carnival; The Duchess of Malfi; The Man of Mode; Hiawatha; Dance of the Forests; The Good Soldier; In The Jungle of Cities; and Mothers & Son.