How is your family ..? 的回答

简简单单就说Fine, thanks 就行了啊
老外这样问就像咱们中国人问吃饭了没有一样,是很随意的问候,不用那样紧张的回答得很书面语,老外还喜欢问How are you doing ? How is everything ? How is everything going ?
都可以回答Fine, thank you, and how about you ?

Fine, thanks
出于礼貌问题，随便问对方”what about you?”