Here is the thing, I was watching Sharp Objects Episode 6 and when little Camile dressed in a red cheerleader suit, waiting for some compliment but her mother kept silent, her sister said:"Mama, couldn't you just take a bite out of her?" I looked up to dictionaries, all I could find is the meaning: to reduce something by a large amount, but I don't think is the appropriate meaning under that occasion (I think her sister wanted her mom to praise her dress or sth.) So could anyone give me an answer? It would be very kind, Thank y'all!
This sounds to me like an association with the phrase "She's so cute I could just eat her up!" A similar phrase is "He's so cute I could just pinch him!"
These are seemingly odd reactions to something cute or adorable.
Stephanie Pappas discusses this in the Live Science article "'I Wanna Eat You Up!' Why We Go Crazy for Cute,":
Ever reacted to the sight of a cute puppy or darling infant by squealing, "I want to eat you up!"? Or maybe you can't help but want to pinch your grandbaby's adorable cheeks. You're not alone. New research finds that seemingly strange aggressive responses to cuteness are actually the norm.
In fact, people not only verbalize these aggressive desires with phrases like, "I just want to squeeze something!" they also really do act them out. In the study, presented Friday (Jan. 18) here at the annual meeting of the Society for Personality and Social Psychology, researchers found that people watching a slideshow of adorable pictures popped more bubbles on a sheet of bubble wrap than did people viewing funny or neutral pictures.
No doubt this was a play on that expression.
Without knowing any better, the first thing that popped into my head at the mention of the red costume and taking "a bite out of her" was not only that she must have looked adorable but also "apple."