Complex sentence: On her return to Italy she sang in several provincial theatres before accepting a contract as the "prima donna" with the Italian opera company at the City Theatre in Odessa, where she was particularly popular and appeared in multiple leading soprano roles from 1850 through 1851.
Split into simpler sentences: On her return to Italy she sang in several provincial theatres before accepting a contract as the "prima donna" with the Italian opera company at the City Theatre in Odessa. She was particularly popular there and appeared in multiple leading soprano roles from 1850 through 1851.