I have a GSD, another breed many are wary of. The thing is, ANY dog, if it's mistreated, can become aggressive. Usually, it's due to fear.
Your dog IS adorable. And my personal experience with pit bulls I've met who are loved, well cared for and well socialized - they are great dogs.
That is the caveat, of course. They need to be well socialized. But, again, there are Goldens who have bitten children because they were abused.
Some breeds, though, are known to be more protective. With Rottweilers, as an example, that is what they were designed for. And GSDs are the stereotypical police dog, Dobies are the ones you see in the movies guarding estates...
With the average pit - I'd be more worried about the dog licking me to death. Pitties are some of the most loving dogs out there, really devoted to their people. At the same time, if your dog somehow got into an altercation with another, guess which dog would be blamed? Is it fair? No, but it's reality.
I face the same thing as a GSD owner. My dog is incredibly sweet, friendly, etc., but I still make sure to be vigilant when we're out in public because I need to protect him.
So keep doing the good stuff you are doing. Socialize your dog, love her and also make sure to get her away from any potential trouble. Protect her from the a**holes who might blame her when their chihuahua aggressively charges her. She looks like an awesome dog and she will give you pure love.