Agreed. We had to have our beautiful boy put to sleep while we were away last year which was heartbreaking. The vet said talk to him as he will hear your voice right to the last second - doing that on facetime was devastating but a small crumb of comfort
I feel for you FP but you absolutely did the right thing - no guilt. In time you will just have happy memories of her and a little piece of you heart will belong to Blue. It should be comforting that she loved you as much as you did her