Wow, I am amazed at the size of your wonderful heart! I am so sad for your loss but you absolutely did the right thing. I am even sadder for poor Allie who was clearly so dreadfully abused that she could never recover. Dogs are the most wonderful, forgiving animals in the world - I once saw a dog who'd been so badly abused, with such terrible injuries, she was going to be pts because they didn't think she'd survive. Four months later and she is with a loving couple who have another rescue, too (older, though) and she is a sweet, loving girl with barely a shadow of her former fear. I cannot think what has happened to your poor Allie that she cannot ever get over it. I am so pleased to hear that there is a place where she can live though, without having to be pts for something that was never her fault.
My heart goes out to you and to her, and I am very proud of you, and happy that you can continue to be part of her life. Hugs, hugs and more hugs.