We began that conversation on Postcards on Monday, after reading “Out of the Loop in Silicon Valley” in Sunday’s New York Times. Facebook COO Sheryl Sandberg chimed in on this site, saying that women tend to be as good at risk-taking as men when doing a deal or building a product. But career-wise, they tend to be more risk-averse, handicapping their entrepreneurialism.

Marissa Mayer, who didn’t start Google but joined as its 20th employee more than a decade ago, suggests that embracing your inner geek is one path to success.

Into this discussion (and into my email box) pops Sukhinder Singh Cassidy, formerly one of Google’s rising stars and now CEO of fashion start-up Polyvore. When it comes to talking careers, Singh Cassidy is also one of the most thoughtful people in the Valley. She told me that I can share with you what she wrote to me this week about aspiring women in tech:

There is a “confidence” gap–even when skills and opportunity are at par with men. Women don’t always go for it, sometimes due to lack of confidence that they can do it.

Women somehow don’t give themselves as much credit for being as capable as men. And for the women who “go for it” as founders or leaders of companies, at least many that I know anecdotally say (as I do as well) that while our mothers gave us stability and strength and self-esteem, many of our fathers helped foster that sense in us that anything is truly possible and seeded the “go for it” confidence.

I do take issue with the sense that men don’t invest in women-started companies. I don’t buy it. I think men and women, as professional investors, are interested in generating superior returns and will invest in any person, man or woman, who can give it to them.

The good news for us is that there is increasing research about the role that “female-oriented qualities”–like empathy, interpersonal skills, etc.–play in leadership and can help businesses thrive. We need to use that to our advantage, recognize that we have more to juggle between the various roles in our lives–as mom, wife, CFO at the office and at home–and do the best we can. But we don’t need to make things enough tougher on ourselves by starting out with yet another chip on our shoulders that the business world in the Valley is somehow fundamentally not fair to women. It risks undermining our own confidence in a task that is already tough enough.

What still needs more work is creating the support systems and infrastructure (both at home and at work) that actually make founding or running a company more feasible for those women who aspire to it. That may be alternate career paths that take into account increased obligations at home when a woman has her second child (often bringing a much bigger juggling act than the first child). Or it may be a husband’s flexible career that allows him to be at home when she’s not. Or maybe better child-care options.

These are key to unlocking potential for women in Silicon Valley. Women coming to the table with the full power and confidence around the roles they have at work and at home is what is all about–to make female entrepreneurship and leadership more of a reality here in the Valley. And everywhere else.

Also, read Sukhinder Singh Cassidy’s 10 Guidelines for career success.