Oh, Mac...
Mac, I'm so sorry for you and your family. I don't know you at all, but my heart breaks for you and yours.
She looks just like my little one...God forbid that children suffer.
FWIW, you have my deepest sympathies. I hope the universe will bring your troubled family a little peace, and soon.
Remember this...we know we can't really change what happens, and that having control of our lives is a silly, comforting myth. All we ever get to have is the knowledge of what we've done.
You gave a beautiful child everything she needed, when she needed it. Her days were happy...better...more fulfilling, because she had Uncle Freddy. Never forget what that means.
I agree that anger and reprisal, while perfectly natural, probably won't benefit you in the end. However, letting the little killer roll through life letting the memory fade is entirely unacceptable.
I suggest that every year, at her birthday, Christmas, Easter (or whatever holidays are appropriate for your family) you send him (and each and every one of his accomplices) a nice card, with a photograph of her inside.
Make it blank inside. Say nothing. Or perhaps write it to her, as you always would...but mail it to him. But never stop...year after year. Make certain he suffers pain for what he did, as you do.
Times like this, I wish I could actually do anything worthwhile to fix it.
With sincerest regrets...
PS...uvw...you need to be quiet. You're out of order.