When she was born, she deserved to be used and enjoyed. You adopted her and unfortunately neglected her, presumably by keeping her in her box in a cupboard somewhere.
Whilst you deeply cherished her and loved her more than anything in this world, she didn't deserve to be neglected like this. You did the right thing by letting her go, allowing another person to adopt her. If there was a SLG/bag protection services, they would have sadly taken her away and given to foster parents.
The thought of her sitting in a dark box in a cupboard deeply upsets me but hopefully now she is given the life she deserves.