After you pass away, someone must administer the living trust. You will choose the person who will administer the living trust, so you can pick any adult who you are confident will be able to effectively manage trust assets and facilitate the transfer of those trust assets to new owners.
You make your choice of who should administer your living trust when you create your trust, which involves working with an experienced attorney to write a trust declaration or trust document. Within the trust declaration, you specify a successor trustee. This successor trustee is the person who takes over the management of the trust after you pass away. The successor trustee administers the living trust.