Can a co-trustee be added to an existing living trust if the grantor has passed away

Some trusts will permit a trustee to appoint a co-trustee to serve with him or her.  Normally, if there was just one "settlor" (person who made the trust), and that trust is to continue on after the person dies, the trust will become irrevocvable and non-amendable at that time.  If there is no provision in the trust for the trustee to appoint a co-trustee, and the trustee does not want to do it alone, the trustee may resign and let the next successor trustee take over.  If there is no successor trustee named in the trust, you would need to file a court petition to have a trustee appointed.