At my work place we throw around homoerotic jokes and comments all the time and no one is offended. I guess it is only if you're comfortable enough with a group that you can ask them to do ridiculous things, kind of funny way. In rework it mentions that you should hire friends, sounds like that girl is the stranger wether it is because she is a girl or wether the men are disgusting pigs - whatever the case.
She can adapt the group become a leader, I've seen it happen with girls or she can cry about being an abused minority. Such is a difference between strong and weak people. Granted we don't come to work to be leaders some of us enjoy just writing code and doodling up layouts and logos in photoshop. In this case a compromise should be found - offsite work on the project. From a coffee shop or otherwise. You know there are other companies to work with as well, maybe with better female/male ratio.
In the end this is a battle of sexes, the chemistry is wrong - men want to have sex with women and when you add in the mix work and being close, you can either make so that you are not attractive to any of the male members of the work force or do something else. Asking men not to be men is just as cruel as asking a woman to be a man. One way to augment this issue is to hire a ton of girls to work in the team to maybe dilute the male collective. But in every case this may lead to different and unpredictable results. You can't just board a pirate ship and expect sailors to behave all gentlemanly at once - maybe pirate ship full of amazons? at any rate this is hugely complicated because people are. Complaining about it won't get you anywhere, acting does.
Most of us want to see more females in the force. Most of the time nerds I know work harder, because they want to strut their awesome code and how well it works before female member of the team.