Is babies a pronoun

No, the Word 'babies' is a noun, the plural form of the singular noun 'baby', a Word for a person.

A pronoun is a Word that takes the place of a noun in a sentence.

The pronouns that take the place of the noun 'babies' are they as the subject of a sentence or a clause, and them as the object of a verb or a preposition.

Example: The babies are twins. They look so much alike that I can't tell them apart.