Of course, the answer is it depends. It can definitely be helpful for family members to hear about general matters like courtroom procedure, how long various steps will take, what you expect to happen and when and what you need generally from your client. Often, the client will be seeking the opinion of these family members, so it is better to have them accurately informed.
On the other hand, it is clearly a problem to have family members in a meeting where the client will be discussing his actions or involvement in a case when that information could later be revisited in court in the form of testimony from those same family members under cross.
Often times, I choose a middle ground. I include family members (with the permission of the client, of course) in that portion of the meeting which will allow them to hear the general information about the case and expectations. I also invite them to ask any questions, and I answer the questions I can without violating a confidence or sharing information about the facts of the case. Sometimes the family members already know the details of the case either because they are witnesses or the client has told them details prior to my engagement in the case. In these instances, I sometimes allow the client’s family to remain for some fact discussion. Usually though, after general discussion has been had and general questions have been answered, I excuse the family members to the lobby and continue the meeting with the client in private to discuss the details of the case. Remind the family during the general information session that attorney-client privilege protects the client and will be destroyed if they are present while you discuss facts and circumstances surrounding your representation. Explain that the privilege exists to protect the client as well as the family (i.e. family could be subpoenaed and forced to testify against the client should the client discuss details with them). In my experience, most family members understand this concept and would not want to be forced to testify against the loved one.
Also, it is important to make sure it is the client’s will being done throughout the representation and not the will of an overbearing family member. I make sure to ask the client privately about matters requiring a choice during the representation.
Overall, including family members in meetings with the client can cut down on misunderstandings and help the family appreciate the hard work you are doing for their loved one. But, keep in mind; there are some things that must be discussed with the client in private even when the family wants to participate in order to preserve the privilege and confidentiality of your representation. In simple terms, make sure the client’s interests always come first. Remember the family wants the best for the client, that’s why they have come to see you, but they do not automatically understand that too much involvement can be detrimental so politely explain this to them and move on.