It's such a short answer, but seems loaded. Far too loaded for her to properly address now, and she's aware enough of that. This being a child, a child with a frightening animal no less, helps keep her slightly in check now that she's been lectured. How would she act if this were her little Elizabeth?

Elizabeth would definitely never act like this. It's not a fair comparison.

"I am also. Very... Very tired."

It's only with a moment's further consideration that she turns to try to walk back to the castle with as much dignity as she can muster.