I used to go to dog parks, but not anymore. Way too many owners don't pay attention to their dogs, and are too ignorant of dog behavior to recognize an issue even if they are watching. And the POOP! They even supply bags at the ones I've been to, but nobody bothers. I have heard way too many stories about dogs being bitten and even killed at the dog park. Your dog has had a bad experience when she was already wary of other dogs, and now will be more so. I would not take her back to the dog park at all. The problem with going earlier is that many people that have "iffy" dogs, try to go on off times so they are less likely to encounter other dogs. So you are more likely to have problems then. Way more dogs become problem dogs at dog parks because they have a bad experience, than become "properly socialized" at a dog park. Try to find your dog a few select, well balanced dog friends, and do a playgroup. Leash aggression is a whole different thing than true dog aggression. It's usual more a result of apprehension around dogs and feeling defensive because she is "trapped" on a leash, and can't run away, so she tries to scare the other dog off instead. Always carry really good treats with you, and when another dog is spotted, start giving her the treats, and stop when the dog goes away. See dog, good things, dog goes, good things stop. This creates a positive association with other dogs. Please don't put her in a situation where she can be attacked again, or she may never get over her fear of other dogs.
