Linda has a good temper, is well-balanced and is able to cope with unforeseen or complicated situations.

well-balanced 是由副词 well（良好地）和形容词 balanced（平衡的）组成的复合形容词。balanced 来自动词 balance（使平衡），加上 -ed 变成形容词。 well-balanced 字面意思是"平衡得很好的"，引申为"情绪稳定、冷静理智"的状态，形容一个人能够保持心理和情绪的平衡。