"Your world is a bit big for me," Stephanie says. "Is it all right with you if I make myself larger?"
"Sure, Stephanie."
"I'd like to grow to fit your room better."
You smile down at her and she smiles back for a while.
You innocently but unthinkingly reply, "I wish that you'd grow to fit the room right now."
Stephanie nods as she begins to swell larger, then realizes the error you've made, as she begins to increase larger and larger faster and faster... to become as big as the room.
Her head hits the ceiling and she lays on her side... wide-eyed at first, but as she slows growing across your living room now, she laughs a giant laugh at you.
"You coulda been a wee bit more specific about that wish, you see."
She's stretched across your twelve foot living room.
You stand up and walk up to her, eyeing her new huge body back and forth. You lay eyes on her now gigantic breasts a few times.
You grin and tell her "At least I wished for you to be as big as the room, and not your breasts. Though I wouldn't mind it, too much."
She smiles with an eyebrow raised. "Lustful are we?" She reaches out her giant hand and lightly (for her) pats your ass.