refrigerator mother

and his mother

Serves as an intensifier for an inclusive noun or phrase such as everyone, anyone, each someone or all someones.

be mother

To pour out tea for others.

like mother, like daughter

A daughter takes after her mother.

mother hen

An outspoken and overprotective woman or person dealing with others' affairs; especially, an assertive matriarch.

Mother Hubbard

Empty.

mother lode

Any source of valuable or useful material.

mother of all

Used before a plural noun to form a compound noun having the sense of: the greatest or largest of (its kind); the most epic example of (its kind).

patience of Mother Teresa

A great deal of patience.