I have the opposite problem. We expected to be getting a male Shiloh Shepherd as a second dog, but the breeder is insane, the dogs are puppy-mills and it was the best decision to NOT end up with one.
My doggie daycare friend, happened to have a litter of German Shepherds, 2 dogs I know very well, and in that litter, were 2 long coats. I got the female.
Our older (spayed) girl, my service dog, hasn't had a friend for 5 years, since our old guy passed away. She has never had a playmate, ever other than our old cat, who is also now departed. I worried constantly that she would be aggressive to another female pup--but turns out she's absolutely happy as a clam. Puppy walks all over her, literally. She grumbles if Daisy is physically too bratty, but gives her her supper, sticks, balls, basically everything puppy wants, she takes. Ellie seems happy to give them to her. (She'll push the ball to her like they are playing hockey) And because she's such a stable minded dog, she gets to be the heavy and help teach puppy manners, like our old guy did to her.
Something she also does, is herd the puppy, she'll help me herd my geese, lost turkeys or pigs who belong next door, and if puppy is losing her little mind, she'll collect her the same way. Circle and bark and lure her back to where she belongs.
Love German Shepherds...they are just the best dogs imo.