Section 755 ILCS 5/2-8 - Renunciation of will by spouse(a) If a will is renounced by the testator's surviving spouse, whether or not the will contains any provision for the benefit of the surviving spouse, the surviving spouse is entitled to the following share of the testator's estate after payment of all just claims: 1/3 of the entire estate if the testator leaves a descendant or 1/2 of the entire estate if the testator leaves no descendant.(b) In order to renounce a will, the testator's surviving spouse must file in the court in which the will was admitted to probate a written instrument signed by the surviving spouse and declaring the renunciation. The time of filing the instrument is: (1) within 7 months after the admission of the will to probate or (2) within such further time as may be allowed by the court if, within 7 months after the admission of the will to probate or before the expiration of any extended period, the surviving spouse files a petition therefor setting forth that litigation is pending that affects the share of the surviving spouse in the estate. The filing of the instrument is a complete bar to any claim of the surviving spouse under the will.(c) If a will is renounced in the manner provided by this Section, any future interest which is to take effect in possession or enjoyment at or after the termination of an estate or other interest given by the will to the surviving spouse takes effect as though the surviving spouse had predeceased the testator, unless the will expressly provides that in case of renunciation the future interest shall not be accelerated.(d) If a surviving spouse of the testator renounces the will and the legacies to other persons are thereby diminished or increased in value, the court, upon settlement of the estate, shall abate from or add to the legacies in such a manner as to apportion the loss or advantage among the legatees in proportion to the amount and value of their legacies.