All Powerful Unicorn

Mona and I got into a heated argument last night.

She started the conversation by saying that if she had a super power it would be being a unicorn.

I stared at her for a moment, contemplating the application of this and said with a nod "okay, sure".

Mona continued with, "I'm still trying to decide if I would be able to switch between a human body and a unicorn body or if I would permanently have a unicorn body."

It's weird to think of your sister in a permanent unicorn body. "I think you might want to have a human body sometimes"

"What if I did have and half?"

"Which half?" I questioned.

"Well it would just be weird to have the bottom half of a unicorn. Everyone would just think I was a horse."

"And you don't think having the legs of a human and the head of a unicorn would look weird?"

"What if I had a pink tale?", she countered

"Then then might just think you are a My Little Pony"

She took great offence to that comment, "I guess I'll just have to be permanently a unicorn. But I'll be all powerful, so I could shape-shift into a human if I wanted..."

"Wait," I stopped her, "You can't permanently be a unicorn and shape-shift into a human."

"Yes I can," she answered, "I'm an All Powerful Unicorn I can do anything! I could shape-shift into a hamster if I wanted."

"But then you would not permanently be a unicorn! You would be unicorn who could switch between the two, but you would not permanently be a unicorn."

"No," she persisted, "I'm an All Powerful Unicorn. I can do anything."

"I'm going to bed," I huffed, "You are not seeing the flaw in your logic."

"Good. Go to bed. Sleep on it and then maybe you'll understand the flaw in your logic."

We are still going back and worth on it this morning and asking others to weigh in. So far everyone has sided with me and my mother thinks we live in a crazy fantasy world.

What are your thoughts on the subject? Can she be both a permanent unicorn and shape-shift into a human? Or does it have to be one way or the other?