I would make sure she is good and hungry, then try again with the training outside with treats. Don't starve her, but just time her training session to be when she's on empty. Also make sure those treats are high value. Bits of cut up chicken breast or steak are usually a hit.
Niko: American Showline GSD 5 years old
Rosa: American Muppet Dog (GSD/Border Collie mix) 5 years old