Some may prefer to use Ms., but they are entitled to use Mrs. Please note that the plural of Mrs. is Mesdames. For example: Ms. Smith and Ms. Jones; Mrs. Smith and Mrs. Jones; Mesdames Smith (when they have the same last name).
Signora is an Italian equivalent of the English word "Mrs." Specifically, the Italian word is a feminine noun. It may be preceded by the definite article la ("the"). The pronunciation is "see-NYOH-rah."