Although this may not apply in Mississippi today it could.  So be careful to at least mention all children.

A pretermitted heir is the child of a person who has written a will in which the child is not mentioned and not left anything. After the death of the parent, a pretermitted heir has the right to demand the share he/she would have received as an heir under the laws of distribution and descent. The law aims to protect these “left-out” children by giving them a forced share of the estate under certain circumstances. This right is based on the presumption that the parent either inadvertently forgot the child or incorrectly believed the child was dead, and did not mean to leave him/her out.

A person wishing to disinherit a child or omit him/her from his/her will, should specifically state in the will: “I leave nothing to my son,” with or without a reason.  A will maker should plan for the possibility that a child may be born or adopted after will execution and expressly mention or provide for the child to prevent this statute from operating.