jhine: So , if a member of someone's family does something that warrants shunning and their family doesn't shun would there be no comeback on them ?
When I was in, they judged this depending on a few factors. If it was a close family member who was living in the same home, then they were expected to avoid spiritual topics or discussion, but otherwise could interact as normal. For those who had relationships that required some contact (business dealings, health issues, etc), they were allowed to communicate only as necessary, and also avoid spiritual discussion.
Aside from that, members were expected to avoid any interaction with disfellowshipped persons. If you were found to be talking with someone who was DF, you probably got a 'reminder' the first time, with the understanding made clear that continuing on this course of action could lead to you being DF as well.
If it seems odd that they specifically forbid spiritual discussion, remember that they expect such guidance to come from the GB and through the elders and ministerial servants. I don't think the WTS trusts the rank-and-file to handle such matters.