She has beautiful coloring. Is it possible that she is a mixed breed? Sometimes accidents happen with breedings. It could also be some kind of deficiency or genetic issue that caused her legs to remain shorter as she's grown. Are you sure she's not hiding normal length chicken legs under that shaggy feathering?
She certainly looks like a chicken though. The only other farm bird I know of that can breed with a chicken is a guinea, and she doesn't look like a guinea at all. Can you call the breeder/hatchery you got her from and ask if they have guineas on the property? Maybe chickens could breed with quail or pheasants too, but I would think you'd notice some very un-chicken like feathering and features from those pairings. Perhaps one of her parents was a guinea cross so she's mostly chicken and only a little guinea? Though I'm not sure whether that kind of hybridization creates infertile offspring, it seems like it would since animal hybrids usually are.
OR you've got the starter bird for a new breed of munchkin chickens (much like the munchkin cat) haha.

She certainly looks like a chicken though. The only other farm bird I know of that can breed with a chicken is a guinea, and she doesn't look like a guinea at all. Can you call the breeder/hatchery you got her from and ask if they have guineas on the property? Maybe chickens could breed with quail or pheasants too, but I would think you'd notice some very un-chicken like feathering and features from those pairings. Perhaps one of her parents was a guinea cross so she's mostly chicken and only a little guinea? Though I'm not sure whether that kind of hybridization creates infertile offspring, it seems like it would since animal hybrids usually are.
OR you've got the starter bird for a new breed of munchkin chickens (much like the munchkin cat) haha.