In 3 of the 4 bands I'm in, there's a female member. 1 just sings (although I think she plays some piano too, but not in the band), 1 sings and plays acoustic guitar and keys, and the last one plays bass (in this band). But she is also a pretty good guitar player, great harmony vocalist (she has perfect pitch, which is both annoying and awesome), and plays cello too (in a small symphony orchestra). So I consider her a musical asset in pretty much any band. As a result, she keeps pretty busy, and is in at least 3 bands currently.
So yeah, my view is whoever shows up that can do that job, male or female is fine.