She wasn't the fighting type, not at all but she didn't want to fall behind if she did need to fight. Plus fighting could help develop her FEAR abilities and with her going into boogeyman training eventually, she didn't want to be thought as of...a damsel or something.
Danny and Lizzy and Xiu could fight, so the Mermaid wanted to learn to fight better as well.
She was just shy, she told herself, not scared of facing another student. Or the possibility of hurting one.
There was a lot of mumbling and pacing, and looks at the doors and then around, and biting of her lip. Lot's of gnawing of her lip with her baby fangs.
Syusaki