Complex sentence: She was the prima donna of the national stage of Norway in the first half of the 19th century; she also belonged to the pioneer troupe of artists at the Norwegian national stage and could be regarded as the first opera singer in Norway.
Split into simpler sentences: She was the prima donna of the national stage of Norway in the first half of the 19th century. She belonged to the pioneer troupe of artists at the Norwegian national stage, and could be regarded as the first opera singer in Norway.