Complex sentence: Charlotte was engaged for some time with Korbinian Niederbühl's son Michael, but when she realizes that Michael has feelings for Tanja, the mother of his child, she separates from him.
Split into simpler sentences: Charlotte was engaged for some time with Korbinian Niederbühl's son Michael. But when she realises that Michael has feelings for Tanja, the mother of his child, she separates from him.