Robin Wright demanded the same salary as Kevin Spacey for 'House of Cards' ? or she would go public
Robin Wright 'House of Cards' salary - Business Insider
Studio had to let themselves be blackmailed in order to avoid PC and SJW scum mafia attacks in the media.
Of course she was offered lower salary because she was a woman actor. And definitely not because Kevin Spacey was much bigger name.
And no, the fact that your character is equally or more popular, than character played by the top star, does not warrant you equal pay.