mother-substitute , także: mother-surrogate

It is considered that the girls have accepted you as a mother-substitute in their very trying situation."

Sand had spent a lifetime being the older woman; in the case of her friendship with Flaubert she went one decade further and became a mother-substitute.

The first human being who appears to the subject after this isolation can easily become bonded as the mother-substitute, or, next best, as a father-substitute.

The need to bond the bio-survival circuit to somebody (or something) is indicated by the giraffe who imprinted on the hunter's jeep as a mother-substitute.

Ghanima had loved Harah, her living mother-substitute, but Alia separated them when Ghanima was three, jealous of their relationship.

I had married Penelope for the person she didn't want to be: a fearless champion of our great British press, my faithful and enduring lover forsaking all others, my lifestyle instructor and the mother of my future children and, in my lowest moments, my own white mother-substitute.