Hey Liz,
It's heart-wrenching to let go of our dear four-footed friends. I sent two beloved kitties off within 10 months of each other a couple of years ago. My Tosspot (aged 19-1/2) looked very much like your Amber, and it was months before I stopped looking for her in her favorite sleeping spot next to the couch every time I came in the front door. You honor your Amber with your grieving, and with your memories. I like the idea of these special friends waiting for us somewhere. They are so truly devoted. With both of mine, my wise and wonderful veterinarian told me that I would know when the time was right for them to go, and (as hard as it was), I did. Don't beat yourself up about whether you made the right decision. I'm sure you did.
Love and hugs, Kathy