Sometimes a client will come to my office and bring a number of other people with her (or him or them). This may or may not be a good idea, depending on circumstances. For example, if the client is a legal minor (I don’t represent them now, but I did once upon a time) I will need the client’s parent or guardian to sign the contract and pay the bills. But sometimes the client will have to tell me things they don’t want their parent or guardian to know about. Things which can be critically important to their case.
On the other hand, sometimes I am being hired by a legal adult. But they want to bring their husband/wife with them. Usually this is OK as whatever they say to me is also protected by the marriage privilege. But not always. And, again, sometimes there are things I need to ask or know about which the client does not want their husband/wife to know about. Worse, what do I do with long-term couples who are not married? There is no privilege then. You can be forced to disclose anything I say to you or you say to me. That’s not good.
There is an exception for circumstances where there is a language difficulty and an interpreter/translator is needed. But every state I know of has a specific statutory exception for interpreters/translators who are working with the lawyer.
This issue is a regular topic among lawyers. We worry about it a lot. There are different approaches we take. Some allow everyone to stay for at least part of the meeting but absolutely ensure that they have some private time with the client. Enough time to be assured that the client has told the lawyer everything. Others prefer to explain the risk to the client and let the client decide. If your lawyer takes this approach, take it from me: s/he’s just being nice. Dump the witnesses and talk to the lawyer on your own. It’s so much safer.