I am not sure that there are many places (if any) that are going to be willing to help train Faith to work with your son. As you stated earlier, most want to offer you a dog. That's because the service training period for dogs is 1 year of intense training at the facility at the bare minimum, 18 months to 2 years is much more common. Not only that, dogs have to be of a certain temperament to do it, and the dominance related behavior Faith is already showing indicates that she may not be well suited to it. (I know all this because last month, an organization for training service dogs to work with muscular distrophy and epilepsy related disorders came and did a 2 hour demonstration and stuff at our kennel club meeting). If you like, I can email them and ask them what options are open to you, but I don't think you should get your hopes up regarding her abilities in this field. This certainly doesn't mean there aren't things that you can do with her! If your son enjoys working with her so much, how do you think he would enjoy junior handling or something like that?
Have you contacted your local animal shelter to see if they know anyone? how about the vet? A friend of ours who volunteers for our local humane society recommend we contact a breed rescue group to get more information on behavior. These groups have a wealth of information since the dogs they rescue they have to find out if they are food aggressive, people aggressive, if they need to be an only dog or go to a home without kids. Try these types of contacts and tell them exactly what you are needing---they may all end up recommending you take the dog for obediance classes, but it's worth a try to see what they say. In the meantime, supervise any contact between the dog and child---a very difficult thing to do with 5 kids----i'm aware of that!!! If this is your little one your talking about, then it's going to be very hard for the child to understand how to behave and handle the dog. Let us know how things go!!
I spoke with a friend who is a trainer today. She is coming Tuesday to work with me and the kids on Faith and her training. She will help out. My son who is autistic really isn't able to do anything sophisticated. I just want Faith to allow him to walk her and pet her. He is very gentle and aprehensive mostly with dogs but LOVES little dogs. Sadly most little dogs don't appear approachable sometimes with their demeanor. Faith is doing great with my littlest ones ironically. I think she will do well. She is willing to do anything we ask---if we tell her what she is to do. That is what growing up is all about right?