Derpy had dreamed of wanting children ever since she was a little filly. She loved the thought of little hooves running through the halls and hearing childish laughter every day. She always preferred a big family, maybe seven or eight foals. After all, children were greatly treasured in Equestria, and to have that many children was seen as a divine blessing.



But after a night of passionate lovemaking with her husband, a time-traveling stallion who owns a peculiar piece of technology called a "TARDIS", Derpy discovered that she was infertile. Not wanting to give up her childhood dreams, she tried everything she could find. Herbal medicines, fertility charms, even the occasional secret dark magic ritual. But alas, it seemed that the very universe forbade such a promising young mare from going against the laws of biology. Infertile is infertile, and that's that.



What made it worse was what happened after the secret got out. Ponies pitied her, but they shared no compassion towards one who could not bear a child. They murmured and agreed that a pony as clumsy as Derpy should not be allowed to have a child, let alone bear one. They even pressured her husband to dump Derpy and find a fertile replacement. Despite the stallion's deep devotion to his wife, Derpy slowly convinced him to leave, not wanting him to be burdened by an infertile mare.



In her despair, Derpy turned to one last resort. She worked hard and long into the night, carving and whittling at what looked like a wooden puppet that represented what Derpy's ideal child would've been, but never was. For months she perfected her craft, and when she thought she was done, Derpy collapsed and cried herself to sleep, whispering a desperate prayer that no one bothered to listen to.



Imagine her surprise when she found a little filly dancing on her table and calling her "Mommy!" the next morning.