I learned Sierpinski's name in high school (he had a pretty carpet, don't you know); I'm pretty sure I learned Hilbert's name from a Nova episode at around the same time.

I first heard Noether's name last year, I think, from some article like this one. Of course, the notion that "where there is a symmetry, there is a conservation principle" came up half a dozen times during my physics/EE Ph.D. studies, but nobody ever suggested that this might be a theorem with a name, let alone the name of Noether.

Your point is well taken, though. A major reason why the female scientists and mathematicians of history are largely invisible, unless you make an effort to see them, is that all scientists and mathematicians are invisible to first order. To get your name out there, even to fans of such things, you have to do a bunch of self-promotion. And self-promotion is a nonlinear endeavor: A little additional friction – from, say, having to lurk quietly at the back of lecture halls and slink in and out the back door of the office, lest you be forced to defend your very presence from a handful of people who are made uncomfortable by it – and you're behind in the fame game.