Mississippi Law provides as follows in regard to renounceation.

“When a husband makes his last will and testament and does not make satisfactory provision therein for his wife, she may, at any time within ninety (90) days after the probate of the will, file in the office where probated a renunciation to the following effect, viz.: “I, A B, the widow of C D, hereby renounce the provision made for me by the will of my deceased husband, and elect to take in lieu thereof my legal share of his estate.” Thereupon she shall be entitled to such part of his estate, real and personal, as she would have been entitled to if he had died intestate, except that, even if the husband left no child nor descendant of such, the widow, upon renouncing, shall be entitled to only one-half (1/2) of the real and personal estate of her deceased husband. The husband may renounce the will of his deceased wife under the same circumstances, in the same time and manner, and with the same effect upon his right to share in her estate as herein provided for the widow.”  MS Code 91-5-25