Aggressive HELP

Stella is close to 2 years old, she has her favorite friends, she ignores
some dogs, BUT others she rarely sees, she goes bonkers. She has never
bitten or attacked. She runs up, then backs off. I guess the only good
thing is that her tail is wagging sometimes, but her hair is up. I heard on
the weekend that there is a person with a dog who 'trains' dogs to get
the aggressiveness out of them. Does any one know where I can find
this person?

Where are you located?

Also, just because her hair goes up does not mean she is aggressive, she could actually be nervous meeting new dogs or unfamiliar dogs.

I am in Brampton, Ontario. You are right, she may be nervous. We
went to obedience school when she was 5 months old, and her very
first day she was attached by a bull mastiff, and that was the icing
on the cake for her. She walked beautifully behind dogs, in front of
dogs, she still does, but when she is confronted by a strange dog,
she barks, lunges, hair goes up sometimes. I want this side out of
her. She is learly of people, walks away from them.

She is learly of people, walks away from them.
I'm sure someone will be able to recommend a good trainer in your area.

As for the leary of people, might I suggest you carry a pocketful of treats and ask people who wish to approach her to give her one? Aussie's can be aloof or leary of strangers and I've found this helps.