Complex sentence: She was a sister to Wilhelm II, German Emperor, Princesses Charlotte, Margrete and Viktoria of Prussia, as well as Prince Heinrich, Princes Waldemar and Sigismund; the latter died before she was born, and Waldemar when he was 11 and she was 8.
Split into simpler sentences: She was a sister to Wilhelm II, German Emperor, Princesses Charlotte, Margrete and Viktoria of Prussia, as well as Princes Heinrich, Waldemar and Sigismund of Prussia. Sigimund died before she was born, and Waldemar when he was 11 and she was 8.