If the decedent left written instructions, those control disposition of the deceased body.

In Mississippi, the following can control the disposition of the body of a deceased person if no written instructions by the deceased, in the order of priority:

(a) The person designated by the decedent as authorized to direct disposition pursuant to Public Law No. 109-163, Section 564, as listed on the decedent’s United States Department of Defense Record of Emergency Data, DD Form 93, or its successor form, if the decedent died during military service, as provided in 10 USC Section 1481(a)(1) through (8), in any branch of the United States Armed Forces, United States Reserve Forces or National Guard.
(b) The surviving spouse.
(c) A surviving child who is at least eighteen (18) years of age.
(d) A grandchild who is at least eighteen (18) years of age.
(e) Either surviving parent.
(f) A surviving sibling who is at least eighteen (18) years of age.
(g) A person acting as a representative of the decedent under a signed authorization of the decedent.
(h) The guardian of the person of the decedent at the time of the decedent’s death, if a guardian has been appointed.
(i) A person in the class of the next degree of kinship, in descending order, who, under state law, would inherit the decedent’s estate if the decedent died intestate and who is at least eighteen (18) years of age.
(j) A person who has exhibited special care and concern for the decedent and is willing and able to make decisions about the cremation and disposition.
(k) In the case of individuals who have donated their bodies to science or whose death occurred in a nursing home or private institution and in which the institution is charged with making arrangements for the final disposition of the decedent, a representative of the institution may serve as the authorizing agent in the absence of any of the above.
(l) In the absence of any of the above, any person willing to assume responsibility for the cremation and disposition of the decedent.
(m) In the case of indigents or any other individuals whose final disposition is the responsibility of the state or any of its instrumentalities, a public administrator, medical examiner, coroner, state-appointed guardian, or any other public official charged with arranging the final disposition of the decedent may serve as the authorizing agent.