I'm in the process of training my 18 month old (she woke me up at 4 this morning asking for her potty and she went)..and we are having some success. I don't know much about 3 year old development, but here goes:
Suggestion: make potty time fun, mommy and me time. I'd go buy a special book or something, and then tell her that you need to go potty and would like to read the book with her while you are both on the potty. I'd also create a happy dance/song to do if she has a hit. If nothing happens after a few minutes, just continue reading the book in another room. I'd make sure you actually have to go and that she had a big drink of water about an hour or so before you attempt this.
In short, I'd figure out a way to mellowly suggest she sit on the potty and make it a real fun time --something special. If you can get her to do it a few times, and then make a big deal out of successes, I'm sure she will take it up real quick.
You could always just tell her that there will be no more diapers and do a three day potty boot camp. I know people say to not push, but I see potty learning as similar to all other types of learning: if not given the opportunity, they will not necessarily do it on their own. Remember how you helped her learn to roll over? Remember how you helped get her to walk? Potty training really is no different. Like the other activities, you can't make them do it, but you can set up conditions that make it more likely that they will try and succeed.