There are a couple of issues here. First, she's just broken up with her boyfriend. Emotionally, that's a difficult time for anyone. Even if she feels that she's ready to start dating again immediately, it will be some time before she's really "over it," and until then the emotional fallout of the breakup is going to be a serious factor. The conventional wisdom is that one should wait a year after the end of a serious relationship before dating again, and from experience I can tell you that's reasonable. For a less serious relationship, it's possible to begin dating again sooner than that, but we're still talking months, not weeks. The reason for the wait is that "rebound" relationships rarely work out successfully. This is so important that I'm going to say it again: Rebound relationships generally don't last very long and the ones that do are almost never happy in the long run. If you're really interested in her as more than just a casual dating partner, it's even more important for you to wait. Right now the best thing you can do is be a friend, and be very careful to make sure it stays a friendship and doesn't slip into more. Having a good and caring friend is what she needs most at this point, even if she doesn't realize it herself. And it may be up to you to make sure it remains a friendship while she heals emotionally. When she starts feeling lonely, knowing that you like her, she may indicate that she's ready to start dating and is interested in going out with you. If she really likes you she might even go so far as to suggest she broke up with her boyfriend so she would be able to date you. Whatever happens, your best bet is to give her time to really get over the relationship. Think of it this way: if you start dating her before she's really over the relationship, you're actually dating her and her memories of her ex-boyfriend. Give her time to get him completely "out of her system." I realize that it's difficult to think of waiting when it would seem she's finally "available" (and possibly even encouraging you to ask her out), but your chances of developing a lasting and successful relationship with her are much better if you take a slow approach. And if it's meant to be, taking it slow will only make it better in the end. Lastly, although you don't ask specifically about the pitfalls of dating someone you work with, you should be aware that doing so is generally a bad idea. If either of you supervises the other, or if you work in the same department or area, it's a very bad idea. It's not such a problem if you simply work for the same company but in different departments or offices, but should still be approached with caution.

I have had experience of this and I had an oppertunity 2 days after their split but i thote she wud fink i was takin advantage and a wk later she was back wiv her b/f! make ur move!