I got two male cockatiels from an over crowded breeder for $10. He said they were wild and I would never be able to touch them. I opened the cage door and let them fly and fly and fly. When they got tired and landed on the floor they stepped up and gladly accepted contact for the very first time in their lives. I still have
Shadow.
I homed a female named
Rosie. She was suppose to love people contact. I nick named her pit bull for the way she not only bit but shook her head to take a chunk.
I never wanted any of them to be anything but happy. I don't trick train and I don't teach them to talk. They learned to talk as kids do.
She may never love you but it sounds like you have enough love to give her.