无心菇凉
[wú xīn gū liáng]
Literally means 'a heartless young girl'. Here, '无心', usually indicates someone without intention of harming others or someone who doesn't think through things seriously or carefully enough. The term can also mean carefree, mindless or indifferent to some extend. 菇凉 is an internet slang, which is a cute term to refer girls generally.