You read the spell and right away you realize she is growing back, her breast are re developing again.
Good you are turning back.
Uh you should look at yourself.
Why?
Because you are getting younger.
What!
You go to a mirror and stare at yourself you were getting younger, it seemed as she got older you got younger.
Whats happening why am I getting younger as you aged.
Look in the book.
You look in the book and it reads:
Make the person back to normal (warning if there is a time limit the reader will become that person's age)
Opps, I didnt read that part.
After a minute your friend had grown back into her 18 yr old self while you had shrunk into a baby again.
You start crying as she walks over to you.
Dont worry Ill take care of you until the spell wears off and if it doesnt Ill age myself and become your mother. But first bthings first