Wiktionary
mother hen
n. 1 (context literally English) A female chicken who bears eggs or chicks. 2 (context idiomatic English) An outspoken and overprotective woman dealing with others' affairs.
WordNet
mother hen
n. a person who cares for the needs of others (especially in an overprotective or interfering way)
a hen with chicks
Usage examples of "mother hen".
She didn't need the help, but Hadi had become as protective of her as a mother hen.
But the chick persisted, and soon was joined by the mother hen, who quickly and neatly consumed all the burrs.