I think it would most likely be a great benefit for your girl to have another dog around. Often living with another dog will bring them out of their shell and make them more confident with dogs.
I say go for it, introduce them carefully at first and give Aria and the puppy some time alone with you so that you still have that 1 to 1 bond.
__________________ Indy, Benjamin and Malachi   There is no psychiatrist in the world like a puppy licking your face- Ben Williams |