Complex sentence: De Ahna was famous for being bossy, snobbish, ill-tempered, eccentric, and outspoken, but the marriage was happy, and she was a great source of inspiration to her husband in works up to and including the "Four Last Songs".
Split into simpler sentences: De Ahna was famous for being bossy, snobbish, ill-tempered, eccentric, and outspoken. But the marriage was happy, and she was a great source of inspiration to her husband in works up to and including the "Four Last Songs".