So, having successfully seen one egg that "rolled out of the nest" and wasn't adopted by anyone through to adulthood

I thought... there's an idea. And so Jian Xin Xin ("Delicate Little Heart"),

having missed the breeding season for Valentine's Day dragons, went out into the Dragon Wilderness and found an abandoned hatchling to adopt.
I won't be able to name or breed "adopted" hatchlings, and they won't show up on my official "scroll," but it'll be fun anyway.