I love the idea of rescuing a baby, if you work with the rescue, they will be able to tell you if the pup is good with other dogs. Many dogs are in rescue because someones lifestyle changes, for example, a new baby. Don't forget to check out the rescue section on YT!
Yorkie Rescues & New Homes Needed - YorkieTalk.com Forums - Yorkshire Terrier Community. Best of luck in finding your girl a playmate.