Even go to church with them from time to time if it makes your wife or sister happy!
I usually suggest to our Sangha members that they do not try to persuade anyone of the "Rightness of Zen Buddhism" or the like. On the other hand, if someone asks ... just speak about what this Way is in one's own life, and answer their questions as best one can. Do not force or lure anyone to a Zen sitting ... but, on the other hand, bring them if they express an interest.
Also, do not try to convince friends or relatives about Buddhist Practice. Instead, I suggest you just be with them as a good, caring, gentle friend or relative ... son or daughter, spouse or parent ... and they will get the point. In fact, if they see a change in you from before ... if they see that you have, in fact, become a more caring, gentle, whole, content person than who they knew before ...
... they will get the message more than anything that can be said in words.