Gu Xiaonuan's worries were purely superfluous. If she suspected that Shen Mufeng was mature and steady at such a young age, that had nothing to do with the environment he grew up in, but more so with Shen Mufeng himself.
The biggest difference between Shen Mufeng and Gu Xiaonuan is that Shen Mufeng, at his tender age, has already seen the coldness of human relationships and understands that outside of family, no one is trustworthy.
Moreover, Shen Mufeng would not waste unnecessary expressions and emotions on those he should not have to deal with.
Although Gu Xiaonuan is also worldly, she is also easily trusting of others.
Gu Xiaonuan believes more in the inherent goodness of human nature. Despite having always lived at the bottom of society, struggling to make ends meet, she still believes that people around her are filled with kindness and love.