Is there a way to translate terms related to the family?
you may want to look at the English translation of the greatest Chinese family novel of them all - Story of the Stone (aka 紅樓夢) - for a sense of what kind of compromises can be made in English without at all compromising fidelity to original, while avoiding the horrors that attend peppering novels with footnotes.

You would probably never want to use personal names instead of titles unless it was so in the original. However it probably is acceptable to go with "Aunt" instead of "paternal/maternal aunt", for example, in English unless it would somehow be impossible to figure out the more precise relationship from context in the novel. Meimei (non-literal variety) are harder- since theres more intimacy implied maybe it would be ok to switch to personal names. 

As for interpreting - good luck. I have a hard time remembering one word for cousin in Chinese, let alone four or five.:P