40 ILCS 5/11-148
A widow's annuity shall terminate when she remarries if the marriage takes place before the date 60 days after the effective date of this amendatory Act of the 91st General Assembly. If a widow remarries 60 or more days after the effective date of this amendatory Act of the 91st General Assembly, the widow's annuity shall continue without interruption.
When a widow dies, if she has not received, in the form of an annuity, an amount equal to the total sum accumulated to his credit from employee's contributions and applied for the widow's annuity, the difference between such accumulated annuity credits and the amount received by her in annuity payments shall be refunded to her, provided, that if a reversionary annuity is payable if to her, or to any other person designated by the employee, such aforesaid amount shall not be refunded but the reversionary annuity shall be payable. If there is any child of the employee who is under 18 years of age, the part of any such amount that is required to pay an annuity to the child shall be transferred to the child's annuity reserve. In making refunds under this Section, no interest shall be paid upon either the total of annuity payments made or the amounts subject to refund. Any refund shall be paid according to the provisions of Section 11-166.
40 ILCS 5/11-148