So sorry to hear about Sarah; your photos showed both her amazing life and how much she was loved. She wasn't "just a chicken," that's obvious.
Bear with me for a few minutes while I provide a book quote that I find comforting.
"You go to a quantum physicist and you say, 'What creates the world?' And, he or she will say, 'Energy.' Well, describe energy. 'OK, it can never be created or destroyed, it always was, always has been, everything that ever existed always exists, it's moving into form, through form and out of form." You go to a theologian and ask the question, 'What created the Universe?' And, he or she will say, 'God.' OK, described God. 'Always was and always has been, never can be created or destroyed, all that ever was. always will be, always moving into form, through form and out of form.' You see, it's the same description, just different terminology."
My interpretation of that is that Sarah still exists in some form. Maybe it's in heaven, maybe it's somewhere else. But she's not really gone, and you will continue to love her wherever she is. You were blessed to have her in your life, and she was blessed to have you.