Hope your spouse has made a request in writing one month prior to maternity leave. If she is covered under ESI she can claim Maternity benefit through ESI.
Anyway ask your spouse now to make a request in writing to the Employer for maternity period salary along with proof of birth and in case of denial she can represent the same the local Labour officer. No employer can deny Maternity Benefit benefit when they fall under the purview of the Act.
6th June 2019 From India, Madras