Ooh tough situation. Ok you're asking if it's possible her story is correct. It's possible. She could've had that one outbreak 10 years ago and never had another. Many people have a few initial outbreaks and never have another. Some others never get a wart, so they don't know they have the virus.
It's highly unlikely that none of her partners have gotten it though. Maybe she thinks this because they've never had a wart, but the virus is very contagious. Just because her incident was very bad doesn't mean they (or even you) would have visible warts. Different people's immune systems react differently.
You should definetely go to the doctor. And if you do end up having the virus, just stay healthy, don't stress too much and you should continue to be outbreak free.