the five mothers

गुरुपत्नी राजपत्नी ज्येष्ठपत्नी तथैव च
पत्नीमाता स्वमाता च पञ्चैते मातरस्मृता॥२३॥
नीतिसारे
gurupatnī rājapatnī jyeṣṭahpatnī tathaiva ca
patnīmātā svamātā ca pañcaite mātarasmṛtā||23||
nītisāree

This is a very important reminder from Niitisaaram, an ancient text which give very apt advice on lifestyle management.

The wife of the preceptor or the teacher, the wife of the elder brother, the queen of the land, mother of the wife and once own mother are all equal in status as mother.
Elsewhere it is said that mother earth and dhaatree, who gives the children breastmilk even though they are not natural mothers are also placed on the same pedestal.

Long live mother-in-laws.