I think under the circumstances, Altheablue, you took the best course of action at that time.
Now for future goes, I think you've got it right by giving the treat once the horse is away from the others (this prevents in fighting over who is entitled to the treat); if you are a helmet wearer consider wearing it when you go out to fetch her in (not to mention sturdy boots and gloves as well); if you can bring someone more experienced along for some hands on tips that would be good; if you have to go it alone, check out what the herd is doing before you head out along with what is happening externally that may stimulate them (for example, you see the tractor coming in from the field pulling noisy equipment - let the tractor go past the herd and out of the way before you go out or you see them all running around for whatever reason - let them settle before you go out); finally if the field is not too large, plan a trip back to the barn that keeps you reasonably close to a fence so you have a place to dash to if necessary. Finally, as the other posters said, keep her attention on you - I don't know what her disposition is like so she may only need a word and tug on the lead or you may ask her to do a couple of circles in different directions around you if she starts to act up.
P.S. Yes, it can be unnerving when a bunch of them start milling around. That's where it helps if you know them individually so you can avoid things like getting in between a dominant one and a submissive one, being active in moving pushy one out of the way, etc.
Last edited by Chevaux; 12-15-2014 at 12:33 AM.