Imagine your daughter tells you there's a monster in her closet then you look in her closet and there's your real daughter in there who says there's a monster in her bed. Bro, you best get the f**k into that closet with her and call the police.
What? It's obviously a changeling. There's no way it always takes the form of that specific little girl. It's probably a bait and switch the changeling does every night to get a snack.