Anything they can do…

MACHO, n, acronym. The initial letters of Massive Compact Halo Object. A relatively dark, dense object, such as a brown dwarf, a low-mass star, or a black hole. [OED]

As an adjective, macho has nothing to do with brown dwarfs or black holes, though it may describe a dense object. It means ostentatiously or notably manly or virile; assertively masculine or tough; producing an impression of manliness or toughness. [OED again]

So why isn’t there a word for assertively feminine, hey? Perhaps it’s not needed because the female equivalent of macho man—the militant feminist—does not assert her femininity. She just maintains that there is no such thing: women could (and would) do anything—say, build bridges, play rugger, kill each other—with as much gusto (and success) as men, had they not been subjected to millennia of social conditioning, oppression and insufficient protein.

Most people believe that there are such things as feminine attributes and that they are mostly rather admirable ones, so it is impossible to imagine a word to describe someone who notably displays them which would not be complimentary, unlike macho, which is always used pejoratively. An ostentatiously masculine man is generally considered contemptible, but what word could one use to characterise a woman who is excessively gentle, sensitive, generous, kind, selfless…and doesn’t care who knows it? I suppose a real macho feminist would say wet.