You don't need your child to sign a will. A will generally requires the signature of the testator himself, and if witnesses (including agents) are needed, the witnesses must also sign. A will refers to a legal act of disposing of a testator's estate or other affairs within the scope permitted by law before his life, which takes effect when the testator dies. In order to make the will made by the testator legally effective, it is necessary to have both the substantive elements of the will and the corresponding formal elements: 1. The substantive elements of the will include 1, and the testator must have testamentary capacity, 2. A will must be the expression of the testator's true meaning, 3. A will shall not revoke the inheritance right of an heir who lacks the ability to work and has no source of income. The property disposed in the will must be the personal property of the testator, 5. A will shall not violate public interests and social morality. The form of will requires that only notarized wills, self-written wills, written wills, recorded wills and oral wills (in case of emergency) are valid wills recognized by the Inheritance Law, and the signatures of the testator or witnesses are required. Legal basis: Article 17 of the Law of People's Republic of China (PRC) on State Succession. A testator may make an oral will in an emergency. An oral will shall be witnessed by two or more witnesses. After the emergency is lifted, if the testator can make a will in written or recorded form, the oral will made is invalid.