Thru tears from reading your post, I am sending my condolences and I know you did the best you could for her. She is in a better place where she is free from suffering. Good that you have her daughter to remember her by as she will help you.
When I had my favorite mare put down last June I thanked her for her gelding son and her daughter who is still with me and I know I freed her from pain and suffering having the Vet do the deed.
My heart goes out to you tonight. Remember all the good times with her.
Hugs,
Joyce