I kid, I kid. My main is a lala. While she might be eye level with a sea of ass, that does not make her a child. She survived the Calamity, deals with pirates-- excuse me, privateers -- and while sure, she's happy and cheery, she's definitely not a child. Maining one, whether I really rp her or not, I would definitely take them seriously. They may be cute, and sure, they can use it to their advantage, but not all will.
I mean, yes, while this may be hard to take seriously:
she can totally kick your ass.