When Dvija males do Pranayama, they chant an expanded version of the Gayatri Mantra, known as the Mahasavitri Mantra. Now the late Sri Vaishnava lecturer U. Ve. Mukkur Lakshminarasimhachariar Swami said this:
strīkaḷum prāṇāyāmam ceyyalām. mantiram kūṟi ceyyāmal, slōkam mūlam payiṟci ceyyalām. rāma mātā kausalyā tēvi prāṇāyāmam ceytirukkiṟāḷ. Avaḷ peṟṟa palaṉ uyarntatu.
Women can also do Pranayama. Instead of performing Pranayama with Mantras, they can perform it with Shlokas. Sri Rama’s mother, Kausalya, performed Pramayama. The reward she obtained is priceless.
The Kausalaya part is referring to this chapter of the Ayodhya Kanda of the Ramayana, where Kausalya uses Pranayama to pray for Rama’s prosperity.
But I’m interested in the part in bold. My question is, what scriptures describe women replacing Mantras with Shlokas when doing Pranayama? And what are the replacement Shlokas?