I think your dog sounds like she has a good temperament (even if not 100% obedient :-)
If she can't be trusted to be called back from meeting another dog, I'd just keep her on a long line when out in that field.
Don't be too upset about your dog!
Because, let me tell ya about the big GSD we passed twice this week....
We are walking through the park. A couple is coming with a big GSD. I see them stop short when they see us, and begin speaking to eachother in urgent voices. At the sight of that reaction, I'm like- uh oh! So Rumo and I move to the furthest side of the path, to the very edge of the woods - there's about 15-20 foot of space for passing now.
It's decided to put their dog in a Down, and he obliges. I think, phew, ok, great training.
We are passing now, drawing even...
and their dog explodes out of the Down! Snarling, snapping, lunging. Owner is dragged towards us.
I am praying: "Don't let that collar break!"
And then, thankfully, we are past and I don't look back.
It's happened twice this week (we both like to walk at dusk, after dinner) and if I could ever speak to that poor couple amidst all the snarling and lunging and the fear that he would kill Rumo if we got close...I would like to send them to this forum.
Anyway...in comparison...your dog is nice...
Rumo ~ rescue shepherd/husky mix