Clearly having flashbacks from when she was a cub, she tries to sit on his lap, instantly reverting back to "Father/Daughter" mode despite the fact that she's as large as he is, possibly even larger. Also, despite all the "biting" she does, no blood is drawn, and she never once punctures the skin. She's being very careful, and just doing the same thing she would have done when she was a cub: nibble on/mouth everything. Especially since her daddy's back, and it's clear as day that she missed him greatly.
