with the unforeseen circumstances and lack of time to weigh every outcome (due to rapidly declining health), you didn’t want to see her suffer. Don’t beat yourself up or even worry about the vet being wrong. I understand Molly was a blessing to you. Get a nice picture framed and be reminded of the good times spent together. I have a mixed breed and although he is doing relatively well for 15, I am constantly thinking I will probably have to deal with him passing away within the next 3 years. You will smile again, breathe, get out in nature and enjoy your friends, listen to a favorite band or artist. None of what happened was your fault.