It was 'noble' of her to come forward with this information.
She married a man of 'noble' [='aristocratic'] birth/rank.
a 'noble' ideal/ambition/cause/purpose
(..) and grasped in its claws my children. But now we must drive it back under the rocks whence it came. Madness has had its day! Forward, march! Rich or poor, noble or common, if we sin, we must atone. Margaery of House Tyrell came to us a sinner. She stood before the gods in the holy sept and lied. (..)2016 TvShow: Game of Thrones Title: Blood of My Blood Season: 6 Episode 6
(..) I'll drink a toast to my new queen, for there is no one fairer. Dear Uncle, will you share my joy and be my royal cupbearer? Drink long and deep, my noble king, from this cup of sweet wine. The last drink he shall ever take. And vengeance shall be mine. Poison! Murder! (..)2016 TvShow: Game of Thrones Title: Blood of My Blood Season: 6 Episode 6