The benefits provided for in section 40-45-13 shall be subject to the following definitions:
1. "Child" or "children" means only the surviving issue of a deceased active or retired member, or the child or children legally adopted by a deceased member prior to the deceased member's retirement from active service or by a retired member prior to July 1, 1937.
2. "Surviving spouse" means only the surviving spouse of a marriage contracted prior to retirement of a deceased member from active service or of a marriage of a retired member contracted prior to July 1, 1937.