Individuals who are beginning the estate planning process may assume it's best to have their adult child(ren) join them in the initial meeting with an estate planning attorney, but this may cause more harm than good.
This issue comes up often in the estate planning and elder law field, and it's a matter of client confidentiality. The attorney must determine who their client is- the individual looking to draft an estate plan or their adult children- and they owe confidentiality to that particular client.
The client is the person whose interests are most at stake. In this case, it is the parent. The attorney must be certain that they understand your wishes, goals and objectives. Having your child in the meeting could cause a problem if your child is joining in on the conversation, which may make it difficult for the attorney to determine if the wishes are those of your child, or are really your wishes.
Especially when representing elderly clients, there may be concerns that the wishes and desires of a child may be in conflict with the best interests of the parent. For example, in a Medicaid and long-term care estate planning context, the attorney may explain various options and one of those may involve transferring, or gifting, assets to children. The child's interest (purely from a financial aspect) would be to receive this gift. However, that may not be what the parent wants, or feels comfortable with. The parent may be reluctant to express those concerns to the attorney if the child is sitting right next to the parent in the meeting.
Also, the attorney will need to make a determination concerning the client's competency. Attorneys are usually able to assess a client's ability to make decisions during the initial meeting. Having a child in the room may make it more difficult for the attorney to determine competency because the child may be "guiding" the parent and finishing the parents thoughts in an attempt to help.
The American Bar Association has published a pamphlet on these issues titled "Why Am I Left in the Waiting Room?" that may be helpful for you and your child to read prior to meeting with an attorney.