As a mom it's wonderful to hear you cared so much for a child in your care. But since she's not your child the time would eventually come when you'd be separated from her. I understand your pain as I loss custody of my children after being a mom for 12 years. It broke me and resulted in my sons suicide. With that said try to teach yourself to not get so attached. And maybe you'll get lucky and run into her one day. My son's daycare lady saw us at the grocery store when he was older. I was surprised she recognized him but she had fond memories.