What to do with a very timid dog?

Question
We have a manchester terrier dog named Rosie. She is a rescue from a very abusive home and is very timid. We have had her now for about 3 yrs and she is about 6 yrs old.
Whenever there is another dog around her she growls at the other dog and then she goes and hides. When our kids and our grandkids come visit she paces and and hides except for one of our grandchildren, she wants to play with him as long as he is here by himself.
Any suggestions to not having her being so scared when people come over and actually relax when we have other people in the house besides us?
Thanks,
Virginia

Another question: How do you pick a german shephard puppy that you know you be easy to train and be the right one for us. We are older and my husband is disabled so we need one that would be of really good nature.  

Answer
Hi, with the terrier, there is nothing much you can do with her except let her deal with things the way she deals with it.  At 6 yrs old, she is set in her ways, and you won't be able to change how she feels about others.  She just needs to deal with them the way she feels GSD, you want to meet both parents, siblings from other litters if at all possible to see their temperment, get references from owners of puppies they have sold before (to get an idea of how those puppies turned out) and if you can meet other relatives of the puppies, you can get a general idea of what the puppies may turn out to be.  There is never a 100% guarantee, but doing as much research as possible can help to make sure that you acquire the best puppy possible.  Hope this helps,

Dawn