Great! Yes, keep her on leash always (until you know she's trustworthy). It only takes a few seconds for a dog to get excited and bolt and playfully cause a tragedy. You could tie a long lead around your waist so you can go about your business and she's safely attached to you.
I'm sure you could train your pup yourself, and the obedience classes will give you confidence. I've discovered that the hardest part about dog training for most people is training 
yourself how to be assertive and consistent. What worked for me was teaching my both my dogs the "leave it" command. I gave very high value treats (like small pieces of hot dog or roasted chicken) as a reward every time they looked away or acted uninterested (staring intently at birds is bad). The goal here is to take away the mystery of these fascinating clucky-flappy creatures and make other stuff seem much more appealing. Before long, chickens will just be part of the background, and the reward will be in the form of yummy poop treasures your chickens leave behind 
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My dog Daisy likes to run really fast, which sometimes stirs my chickens into a frenzy, but she doesn't chase them. And if she does get into anything I don't want, she'll stop immediately if I say "Leave It!"