Suggestions by @casstherose

Cary Elwes

as Jaime Lannister in ASOIAF

Score: +1

Apollonia Kotero

as Arianne Martell in ASOIAF

Score: +1

Nicole Kidman

as Cersei Lannister in ASOIAF

Score: 0

Lena Headey

as Cersei Lannister in ASOIAF

Score: +1

Q'orianka Kilcher

as Elia Martell in ASOIAF

Score: +1

Layla Burns

as Sansa Stark in ASOIAF

Score: +2

Pernille Kaae Høier

as Daenerys Targaryen in ASOIAF

Score: +1

Sophie Turner

as Sansa Stark in ASOIAF

Score: +1

Millie Bobby Brown

as Margaery Tyrell in ASOIAF

Score: +2

Natalie Portman

as Margaery Tyrell in ASOIAF

Score: +1

Nicholas Galitzine

as Renly Baratheon in ASOIAF

Score: +1

Natalie Portman

as 2010s in What Actresses Could've Played Margaery Tyrell in Various Decades?

Score: +1

Nicholas Galitzine

as Renly Baratheon in House Baratheon

Score: +1