The dictionary mixes them too, then.

  woman |ˈwo͝omən|
  noun ( pl. women |ˈwimin| )
  an adult human female.

And so does the author of that post - I looked at the talk page and it says "female" all over the place. You're proving my point.

If those two words did in fact have the distinct meanings you imply, that would solve some of the problem.

"female" can refer to gender just fine.