I don't understand your question. Are you really saying that women can't be software engineers? Because that clearly isn't true.
There are many different jobs in software engineering that are mathematical. The most advanced, best paying jobs are developing new technology in the most cutting edge fields. These cutting edge fields change from decade to decade, but right now they include fields like speech recognition, image processing and robotic vision.
The women and men running projects (I am talking about chief scientists, not project managers) in these fields usually have PhD's and a very deep understanding of mathematics. These jobs make easily $150,000 - $300,000 and up and require advanced mathematics daily. Under them are group of experienced research programmers doing a lot of the design and implementation. They can make $70,000 - $150,000 a year.
Of course there are lots of other types of jobs in software from upper level developers and software architects to lower level programmers to web designers etc. These are still well paying ($50,000 - $100,000 is typical for any of these technical positions with some experience). But if you love mathematics and want to go into software engineering, you really should be in a research position.
Project managers are not the same thing as programmers (and project management does not require the advanced understanding of math that many software engineering positions require). Project managers have to be good at organization and schedules and at getting people to talk to each other. I wouldn't recommend project management as a career to the original poster who says she wants a career in mathematics.
Gender doesn't matter. A couple of years ago I worked for a woman; a brilliant scientist in the field of speech recognition. Although there are more male software engineers than female right now (this is changing), if you are talented and educated you can do very well in engineering.