[Butcher'sDog2]

Brodster, the situation you described is not an indication to me whether the dog is ready or not ready for civil work.

As far as that situation goes you need to decide how you'll handle it in the future. If you let it go it is fairly certain that she'll continue with this behavior. I can't be sure about what happened exactly to stimulate the dog and whether her reaction was merited. Only you know what you felt, how those guys behaved, and how close to you they actually got. My gut feeling is I would've given an out and a heel command and let her watch a little more. Next time pull over a little away from the action and give her a heel command to steady her so she can sit at heel and observe what's going on.

As far as what age to start civil work, there is no age. I start dogs civilly not in prey. Some fast maturing dogs can do it at 10 months, others at 2.5 years, yet others never. I just start and look for signs of forward aggression, a stance, a look, a growl or a bark, then build on it. If there's nothing to build on I wait and try again at a later time or push harder to make the dog come out or disqualify it. There aren't too many helpers that know how to do this right.

Edit - I missed that the bitch is 3 years old now. I thought you're still dealing with a young bitch. By now you know whether she's trigger happy or level headed.