A boy crazy daughter can be daunting, especially if she might start acting in sexually suggestive or aggressive ways. One thing you can do is to make sure you talk to your daughter early and openly about sexual and romantic issues, even if you find it uncomfortable.
First, when you discuss sex and sexuality (do talk about more than just mechanics), you can also deliver the message that sexual feelings are natural but that doesn't mean it's necessarily appropriate to act on them. You should certainly also tell your daughter that being sexually coercive is never acceptable. Second, you should talk to your daughter about more than sex, but include talks about romance and love. You want your daughter to understand that a relationship with a special boy should be about more than sex, but also keep her expectations realistic. If she holds onto Prince Charming or "one true love" fantasies, she's more likely to invest great resources in making sure she finds her "one and only."
Another topic to discuss is her self-esteem. Current culture is highly sexualized and very focused on pairing up, so it's easy for your daughter to get the message that she must have a boyfriend to validate her worth. Make sure you are helping your daughter, in word and deed, to learn to appreciate herself. The better she finds her own internal worth, the less likely she will look to approval from boys.
As a practical matter, you can also limit the scope of your daughter's social activity in mixed-sex groups; this is more appropriate in the tweens/early teens), or regulate how and when she can interact one-on-one socially with a boy. If many of her girlfriends are older, they might be (unintentionally even) influencing your daughter to mature more quickly than she's truly ready to do.