The possessive form for the plural noun mothers is mothers'.
Example: The mothers of several students have formed a mothers' committee.
The singular possessive form is mother's.The plural possessive form is mothers'.
Mother is a noun, not a pronoun. The possessive form is mother's.
mother's name is the correct possessive form
The singular possessive form is heart's; the plural possessive form is hearts'.
The possessive form is subsidiary's.