Who is this grown up acting like a kid?

f(x) Amber seems like growing like a kid. She uploads a photo of on her instagram account and wrote,

"IM A BIG KID NOW! (daddy @superspider_pig & mommy @ywywmlt )" In the photo, Amber is like a happy kid walking happily in between her parents. Her so-called 'daddy and mommy' are actually her friends who ride with her childish act.

Fans left comments such as, "Oh Amber you're so adorable!","She's so sweet! I though they were her real parents.","Have fun Amber!" and so on.

Is she like this when she's with her real parents? Amber really knows how to have fun!