Honey Boo Boo -- I'm Not Leavin' My Sis For a Dumb TV Show

Honey Boo Boo is mysteriously bailing on public appearances ... and we know the reason -- a smashed Pumpkin.

Boo Boo was a no-show this morning on "GMA" and we're told she won't show up at Katie Couric's show either.

Turns out the kid's family ties are more important than mugging for a camera. She's been spending time in the hospital with big sis Pumpkin, who was badly hurt in the family car accident last week. Pumpkin suffered severe chest bruises, a concussion and weakness in her legs.

She can be annoying, but she's a good sister.