That is SO sweet... and emotional knowing that your Mom probably felt the same way.
If you're lucky, there are so many "favorite" times with others that you love. I cannot imagine trying to choose one. Sure as I would be about to say one, another that I hadn't thought of in forever would pop up.... over and over.
My problem was that I couldn't remember much about my mother. My childhood was not all that comfy, I was terrified of my father, and my mother remained silent much of the time, possibly terrified of him too.
I think one of my favorite memories of her would be, now that you've jogged my memory, one event shortly before she had the stroke that took her from us. I said
I can still see her smile.
Awwww.... that sounds like a very sweet moment.