[paulapoo]

I would probably do what yapper suggested and try to introduce myself to the people and try to develop some sort of relationship with them and let them know it makes you nervous when their dogs approach you, your sister, or your dogs. I'm not one for confrontation either, so if this doesn't work I would try to go to higher powers or leave the park. I've had to quit walking my dogs in my neighborhood because of unleashed dogs approaching us in what appears to me to be an "aggressive" manner. Luckily, I have a large back yard so they get enough exercise, but Otis REALLY loved his walks.