Toon Zelda does stuff like that too! (Spoilered so Ino doesn't yell at me againShe gets her body stolen, and wants to stay behind waiting for Link to return. She only comes with you because Anjean forces her. In the final battle all she does is pray while you have to protect her.
Tetra on the other hand, in a pirate, not scared of anything and even though she's the youngest of the crew she still leads them. In the final battles she helps you with shooting light arrows at Ganondorf. Also unlike Link and the rest of her crew she has the guts to actually enter that ghost ship (not her fault she didn't have a phantom hourglass with her).
She wrestles with MalladusZelda so link can get a shot in with the Bow of Light. Then, after getting her body back and powering up with prayer-power, you provide the distraction while she shoots Malladus with the Bow of Light. Then she helps you stab Malladus in the face.