Anecdotes Dramatiques

Anecdotes Dramatiques has both an account of la Maupin's life and the fact that the lead in Tancrède was written for her. On the latter, it has this to say:

Tancrède, Tragédie-Opéra, avec un Prologue, par Danchet, Musique de Campra, 1702.

Le rôle de Clorinde fut composé pour Mademoiselle Maupin. Sa figure hardie & son air Cavalier parurent avec le plus grand éclat sous le casque & la cuirasse ; & la beauté de sa voix, qui étoit un bas-dessus admirable, réunit tous les suffrages que la singularité du Costume avoit déja prévenus.

Which mechanically translates as:

Tancred, Tragedy-opera with a prologue by Danchet Music by Campra, 1702. The role of Clorinda was composed for Mademoiselle Maupin. Her face, & her bold Cavalier air appeared with the greatest splendor under the helmet & the shield, and beauty of her voice, which was a wonderful low-top, we all agree that the singularity of costume had already been warned.

My (on-going) transcription and translation of the longer section on her life can be found on my old site along with Parfaict's Dictionaire.