Chivalrous is an adjective that is generally used for men. Is there an adjective that can be used to describe women in a similar fashion?
Being chivalrous only applied to men, because only men were able to become knighted. However, that does not mean a woman could not follow the Knights Code.
There's no reason why a woman can't be chivalrous.
Despite popular belief, in the Knights Code of Chivalry, gender is only really mentioned once. Most of it has to do with being honorable, helping the weak, and being merciful: