Which character on the HBO fantasy television series "Game of Thrones" is also prominent in author George R.R. Martin's series, "A Song of Ice and Fire?" 
Sophie Turner:  Turner made her professional acting debut as Sansa Stark on the HBO fantasy television series "Game of Thrones" (2011–present), which brought her international recognition. Sansa Stark:  She is a prominent character in Martin's award-winning "A Song of Ice and Fire" series.
Sansa Stark