Reaction to the dogs next door.

Question
I have a 12 week old female boxer. I got her at 9 weeks. I have a big fenced back yard, and marked a spot for her to go too as her bathroom/potty spot. She is doing well at the house training, and goes to that part of the yard to do her thing. The house to left has 2 dogs(1 golden retriever, 1 schnauzer, both males). When I take her out to run/play in the yard they both come to the fence a do what dogs do and bark and raise a commotion. At first I started out walking slowly to the fence and not making a big deal out of the other dogs. I would get her to about 10 feet away and she would run away. I would then move away from the fence and play with her and pay no attention to the other dogs. Now at 12 weeks she will still go up to about 10 feet away, but now she will bark back at them for a few seconds then run off. She will have her little tail, and the hair running down her back will be  sticking straight up. I don't want her to become aggressive to other dogs. She doesn't get this way when I take her for walks and we meet other dogs, or have when I have taken her to meet my coworkers dogs. She also is very good at the Vet with all the other critters in the waiting room. What is the correct thing for me to do when she is barking at the dogs next door.

I have taken her to something new every week, walks in the woods, walking in the city, rides in the truck, meeting as many new things and people as I could think of. The Vet told me to keep her away from other dogs till she is 14 weeks and she is complete with her shots. Is this correct? And I'm I doing the right thing?

Sorry about the long post,
Thanks

Answer
First, she is still in a learning stage and simply learning to copy the barking neighbor dogs by thinking "that's what you are suppose to do,"

They learn from their mom, and imitate and copy, and continue copying any older dogs as example.

Secondly, the vet is correct. Even though she has had her vaccinations, sometimes they are not 100% until an older age. He/she is being cautious for good reason.

I would verbally reprimand her when she returns the barking at the neighbor dogs, leash her immediately, and march her away from them, maybe into the house for 5-7 minutes. Then, take her back outside and repeat if necessary.

She will associate your reprimand routine to the "bad behavior" of returning their barks.