YC is approaching the acceptance rate of Berkeley PHD - due to the ever increasing supply of applicants, mostly. The classes have actually gotten larger. So any feelings that "I probably won't get in" are probably true for any gendered applicant.
By all means apply! But have a backup plan. I have known people that have looked for funding only from YC. That's just as silly as only applying to Berkeley and then giving up on your PHD if you don't get in. As they say in football, that's not a high percentage play.
There were plenty of women PHDs at my graduate school, and men too! So I know people of many genders can navigate processes with lots of rejection.