In order for a person to buy life insurance on someone else, that person needs an Insurable Interest in the person they wish to insure for life insurance.
Insurable Interest means you either rely on the other person for some form of financial support, or that you would suffer a financial loss upon the death of the person you wish to insure.
Since many adult children may either receive some form of support from their parents, or be responsible for covering the cost of their parent's final expenses, they can buy funeral insurance on their parents.
Learn more about how to buy funeral insurance for your parents.