For me, both sentences sound a little weird. For the English part first"I have three members of the family" I think u mean "there are three members in my family" because "I" cannot have "members" ,it is weird. For the Chinese"我有三口人","我"is the subject,"有"is the verb,我有“三口人”is really strange for the same reason. In general,we say我家有三个人, and“口”is not a formal quantifier for person,if you want to say "three people/persons", you'd better say 三个人 because "口" is used as an old idiom and knowing but not using that would be a wise choice

нет... китайцы не говорят "я имею людей"

我家有三口人

Can teach me to learn English? Would you please join my SKYPE:fanqingqing118, I can help you learn Chinese,

The family is lost. Correct sentence is:我家有三口人