I guess it depends on what question the OP was asking (note: my answer pertains to comics, not to the cinematic continuities). No matter what the actual question, my answer is that there probably isn't one.
If we're talking about prominence, I'd guess that Captain Danvers-Marvel has the current claim on that title in the comics, because she's the one they've been pushing the hardest. Fifteen years ago, I might have said that role belonged to She-Hulk, and Storm certainly deserves a mention. However, the fact that the prominence seems to shift from one character to another suggests that there's no one with Wonder Woman's consistent lead role.
If we're talking about a character that fills Wonder Woman "ecological niche" in the MU, there definitely isn't one. At least, not exactly.
Wonder Woman was created as a superhero for girls to identify with, and as a symbol of feminine strength and independence (whether successfully executed on a consistent basis or not). The vast majority of Marvel's original female characters (not counting name retreads) were created as either appendages or derivatives of male characters. None were created as a woman's hero.
A case could be made for Storm, but if you go back to the first 20 years of her history, her story was more about reconciliation of her humanity with the goddess she believed she'd become than either her race or gender. Another case could be made for Ms. Khan-Marvel, but her story is more about diversity in a broader sense than in feminism. Yet another case might be made for Captain Monica-Marvel; aside from the name, she was created and forcefully cross-promoted as a unique and standalone character, but her story was never really about feminism either. Some might point to Power Princess of the Squadron Supreme, however, aside from being an adaptation of Wonder Woman, her native civilization was about genetic and philosophical advancement (they were basically her earth's version of the Inhumans), and her backstory was more about advancing society as a whole than about the role of women in it. Oddly enough, the best case might be made for Thundra, even though she debuted as both an antagonist, and as something of a sendup of Wonder Woman.
Ultimately, I don't think anyone's created a character equal to Wonder Woman, neither as a feminist symbol, nor in terms of consistent popularity.