她是个慢性子的女孩儿。

She is an unworried girl.

“快点，你个慢性子，”法兰克说，一边加快了步伐

"Come on, slowcoach," said Frank, pushing up the pace still more.

他做什么事情都慢吞吞地。真是个名副其实的慢性子。

He does anything at at a snail's pace.He is really a slowcoach.