However, I've been at the receiving end of hostility from a female group mate. Mind you, she's only hostile to me, but deferring to the two guys in our group. It even reached the point that she e-mailed our professor to let him in on our group's supposed lack of direction and leadership (we assumed she was the group leader because she's been bossing us around), apart from saying she's doing all the work (not true). Tonight, we had the chance to clear the air. She apologized after I told her, "I feel like I can't say anything without you jumping down on my throat. Every suggestion I make, you shoot it down immediately." Now, after our client accepted a suggestion I came up with, suddenly I'M the new leader. How that happened, I've no clue.
Nevertheless, this group project made me realize the value of taking things a step at a time. And yes, always speak up for yourself. Otherwise, people will try to step all over you.