Duoduo can do so much better. I'm normally for less-submissive/damsel women in wuxia stories, but this chick isn't that - she's just a tsundere who tries to seem more powerful by putting down others whenever she gets an idea in her head that she feels justifies it. She'd probably been wanting to shit-talk our boy this whole time and finally found a smudge to do it with.
It's clear she likes Duoduo but just sits there and refuses to make it actually happen, and even tried to tarnish his brother's reputation so he'd undoubtedly leave his side and only look up to her. If she's even that intelligent, it seemed like everyone thought she was slow.