I'm so sorry to hear of the loss of your beloved Maggie. She was such a beautiful dog! I can tell from your pictures that you were the best of friends and how very much she meant to you. You gave her the final gift of love by releasing her from any suffering. That was a great act of kindness. She was given to walk with you for awhile and then a Voice greater than yours called her name and she had to go. But love is the strongest force and it is eternal!
You will always have her in your heart and she will always have you in hers.
Nothing can ever change the relationship you had with her. It's there forever. One day the sadness will be replaced by smiles when you think of her. But for now please know you have my deepest sympathy for the ache you have in your heart.
RIP, sweet Maggie.