Spearhead? None. That would indicate it leads the way, and it did not.
Hedda Gabler does do some modest work at showing alternative ways for people to act. Hedda herself is a striking character, full of extroverted energies. She is intelligent and sexual, and works to shatter some social expectations about women. Likewise, her desire to shape a person's destiny fits with the new woman's desire for self-determination.
However, her value as a symbol of new woman is limited by her suicide, and, before that, by the emphasis on sexual/romantic control over men (rather than sexual desire for her sake). The suicide does show what happens to women of power when they aren't allowed to live those powers.