4) Make Cera a LIKABLE character. Honestly she is right meanie and acts shelfishly towards everyone! Her only redemption is right at the end and then to see her actually looks sad when Petrie dies. The FIRST time she shows that she cares about anyone. I love how strong willed she is but she needed more fleshing out. And some more time after that so we can like her.
I am not entirely sure how I feel about this. Cera wouldn't feel like Cera if she were suddenly nice towards everyone. I feel she was meant to act as a foil to Littlefoot. And besides, not all children are 'sweet little angels'. Having Cera act jerkish portrays this, and it made the group dynamic more interesting. It just wouldn't be the same if she were too nice.
Also, what do you mean that her "only" redemption is when she was sad for Petrie? I would think that her going back and offering help to stop Sharptooth would count also. If she hadn't come back, they all could have been killed.