Tradition and history — not medical advice
What did Suśruta prescribe as a new mother's diet?
The Suśruta Saṃhitā lays out a graded diet for the weeks after birth: thin gruels first, then rice and a meat broth, moving the mother back to her ordinary food only once her digestion has recovered.
What the texts say
Suśruta Saṃhitā — Śārīra-sthāna 10.15
When the discharge gets normal (i.e., on the appearance of healthy lochia), the mother should be made to take for three days a gruel (Yavāgu) prepared with the decoction of the drugs constituting the Vidāri-Gandhādi Gaṇa and mixed with (a good quantity of) clarified butter or a Yavāgu prepared in milk. After that a meal of boiled Śāli-rice and a broth made from the meats of Jāṅgala animals boiled with barley, Kola and Kulattha pulse, should be prescribed for her, taking into consideration the strength and the condition of her appetite (Agni or digesting power).
Kaviraj Kunja Lal Bhishagratna, An English Translation of the Sushruta Samhita, Based on Original Sanskrit Text, Volume II (Nidāna-sthāna, Śārīra-sthāna, Chikitsā-sthāna and Kalpa-sthāna) (1911). Public domain.
What modern guidance says
Eat plenty of fresh fruit, vegetables, salad, wholegrain cereals and wholemeal bread, and drink plenty of water.
NHS (reviewed 2024-04-25)
Speak to your doctor or midwife
The text also names herbal formulas for the mother's own complaints, not shown here as recommendations. If you're breastfeeding and considering any herbal remedy, ask your doctor, midwife or pharmacist first — some herbs are not well studied for breastfeeding safety.