All of the examples you gave mentioned her being loud in some way or another. I know some kids are very sensitive to people addressing them in a loud voice, either being unused to it or associating it with getting yelled at for doing something wrong.
At her age you could start really working on the appropriate volume idea, otherwise known as the indoor/outdoor voice concept. Just like it is not appropriate to YELL inside at night when people are trying to sleep, or in a nice restaurant, or at church, it isn't appropriate to address friends or possible friends) in a loud aggressive way. It is appropriate to giggle and screech while running around outside playing with them and in that situation it probably wouldn't make them cry. You could even demonstrate how her actions might seem to other kids, having her pretend to be the other kid and you pretend to be her.
If it is really troubling her an explanation like this should help.
