Well, the "too good" part is true, in the fact that they make her too much of a pure, goody two shoes. Much like Steven Universe. Being "too good" is a bad character trait.
It's been a sweet minute since I watched it, and I prefer to forget shitty shows. Tell me, does she have any defining character flaw? And her being wrong That One Time, isn't a flaw. What is a defining bad quality of her character?
I ask this, because, last I remember, she never had one.