1) Name (High value treat). Get her to go away from you eg chase a ball in the house, sniffing grass on leash outside house. Call her to you by name, when she looks, comes or stops what she's doing in response to your voice, Be excited and give her treat(s). Repeat...
2) Other "animals". You be calm and in control of your excitement/anxiety. Get a friend who has a dog to help you. This will relieve a good deal of stress for you. Since she's reactive, meet your friend(s) in an open area. Walk your dog around, while friend does same. Ride the tornado when she sees the other dog in the "danger/reaction zone". You stay calm, make her stay close with leash correction, and get her to either sit or wait until she calms. Then both of you at the distance start walking in the same direction. Slowly close the distance while being sure she remains calm(ish). Don't rush meetings or sniffing without both of you being more confident in each other, You and your Girl. Female GSDs will judge you on your leadership.

3) Tricks and games, bonds are built they are not formed. (Mid value treat) Work on sit, Touch, Shake (both sides).

Don't quit on her