凉情凉心姑娘百毒不侵旧情旧爱少年是否还在
[liáng qíng liáng xīn gū niáng băi dú bù qīn jiù qíng jiù ài shăo nián shì fŏu hái zài]
This nickname expresses the idea of a girl who has become emotionally detached (cool-hearted) because of many hardships and is immune to any negative influence (unharmed by anything poisonous). It questions whether a former love interest still feels the same.