Man.
I am not a big fan of dog parks. I think they are more for the people than for the dogs. There is a dog park fairly near to where I live, and I visited it three or four times to "check it out" before bringing my dogs along.
Way too many idiots with large unruly and uncontrolled dogs running loose, having near-confrontations with other dogs and people. I had one of these largish dogs run up to me and curl a lip and show some teeth. The twenty-something doofus (can I say doofus on this board?) smiled and said that he was friendly and wouldn't bite. This of a dog that was giving me the Canine Stare with a hint of hackles.
I'm sixty-five. I came late to the dog game - early thirties - but when I fall, I fall hard. For the last 35 years I have lived with dogs in my home (not tied in the back yard), trained dogs, shown dogs and (for about 10 years) bred dogs. During this time (and still) I read everything I can get my hands on about dogs. I love dogs. Period. People sometimes not so much, but that is another story.
Do I think I am a dog expert? No way. I'm "still learning". Do I know an aggressive dog when I see one? Can I read dog body language? You betcha.
Never did bring my dogs to the dog park.
Anyway, I think you handled the situation perfectly, and a lot better than I would have. Good on you.
If this woman would have kept going at me like she kept going at you (I've done this before) I would have smiled very sweetly at her and said: "Excuse me, can I ask you a question?" The smile gets them off base, they generally then give the affirmative. Then: "I'm curious. Just what part of 'I want to move past it' do you fail to understand?" Still smiling. It works really well if there are other people present who are listening.
I wouldn't try this with someone who had smoke coming out of their ears, of course, but there you are.
You go, girl.
Going back to lurking now.
Cudedog