The waif Marie is adopted by a French army regiment, falls in love with a Tyrolean youth called Tonio, but is carried off to live with the Marquise of Berkenfeld who plans to turn her into a genteel lady and marry her to an aristocrat. The Marquise turns out to be her long lost mother who lets her marry Tonio in the end.

An opera about a little girl who was adopted by a whole regiment.

En el pueblo de Fuenteclara no nace un niño desde hace diez años. El príncipe envía un regimiento de lanceros. El duque y su esposa tienen una niña y un teniente y su mujer, hermana del duque, a un niño, pero como el duque deseaba varón su hermana cambia el del teniente por la niña, que adopta el regimiento y crece como la cabo Rosaura. El teniente Orlando, el supuesto hijo de Basilio, va a Fuenteclara y toma a Rosaura por asistente, pues por una infusión tiene voz masculina. Ella siente celos de Orlando cuando baila, pero él ya sabe que ella es mujer. Ambos se enamoran y pasan por maricas pero el duque y su hermana aclaran cual es hijo de quien y que son hombre y mujer. Los jóvenes se casan.
Adaptation of Donizetti's opera. In the town of Fuenteclara, not a single boy has been born in 10 years. The prince sends a regiment of lanceros. The Duke and his wife have a girl and a lieutenant and his wife, sister of the Duke, a boy, but as the Duke wished for a boy, his sister raises her switches the babies. The girl is adopted by the regiment. Lieutenant Orlando, supposed son of Duke Basilio, goes to Fuenteclara and takes on the girl, Rosaura, as an assistant, who is pretending to be man. She is jealous of Orlando when he dances, but he already knows the truth and they fall in love. When the Duke and his sister clarify whose child is whose, the young people can marry.

Comic opera about an orphan adopted by a regiment in Napoleon's army. Preceeded by a conversation with Beverly Sills.