I've looked very briefly into that for our son, who will be turning 7 in August. The two services I found were aimed mostly at people with serious physical disabilities. It takes about two years once you're application is approved, and you have to do a two-week training period. I got a bit disenchanted because of the hoops you had to jump through =) I think in our case, I'll look into it again when he gets a little bit older. Your daughter has different needs, and might need something like that at a younger age. Run a search for "service dogs for children"- it should turn up some information for you.