Please don't beat yourself up, BBH. Your priorities were/are solidly in the right place. Sam needed all your attention and as sad as it is, the same outcome could have happened even with your full attention to Dolly.....but most importantly, you were with Sam, fighting for her life. She needed you 100% and you gave her 100%. You did the right thing. It is NOT your fault Dolly got sick and died. I truly believe that. Dolly knew she was loved and cared for during her fight, and she had a wonderful last three years, likely the best of her life. You gave her a wonderful gift.
Now go give Sam a big hug and one for yourself from me. And for everyone else in your household. SMOOCHES!!!!
Sorry about Dolly.
Now it's time to Stop second guessing yourself. When your child is sick- everything else in your life was less important. That's just being a good Mom.
You were good to your sheep, but these things happen.