"Turn back to normal." you say, nervously.
Her body reshapes back to her normal one, and she looks back at you. "What are you looking at, twerp?"
"Nothing, nothing." you say.
You think, and you realize you have the power to get people to do whatever you want.
You wonder if it'll work on yourself, and you say...
"I want to be a really hot girl, while keeping my real mind and personality."
Suddenly your body reshapes, and your body starts getting curvy, and breasts grow.
Next thing you know, you're a really hot girl, in your clothes.
"Woah." you say. You then look at your sister with an evil grin.
"What?" she says, a bit scared.
"Be exactly like the real me, both physically and mentally."
Suddenly her body reshapes, and next thing you both know, she has your body. Her clothes are now too small for her, and she stands there confused.
You sigh with relief and say, "I want our bodies to be so they fit each other's clothes."
Your body reshapes to be in the same height and shape as your sisters, and your sister stays the same, as she already had your body.
"I'm a hot girl that can fit into her clothes, and she's me...I want her to be nice to me."
Suddenly she shakes her head and looks at you, then at herself, now himself.
"Sorry sis, I don't know what I'm doing in your clothes, and you're in mine. Let's go change."
You nod, and head up to your sister's room, and she heads up to your room.