好菇凉配狗可惜了
[hăo gū liáng pèi gŏu kĕ xī le]
The nickname plays on words, with “好菇凉” sounding similar to “好姑娘” (a good girl), and “配狗可惜了” implies something along the lines of “it's a pity if a good girl is paired with someone unworthy.” It expresses a feeling of disappointment when a good person encounters negative situations or mistreatment.