Complex sentence: In 1988 she married Siddhartha Das with whom she had a daughter, Sheena, in February 1989 and a son, Mikhail, in September 1990.
Split into simpler sentences: In 1988 she married Siddhartha Das with whom she had a daughter, Sheena, in February 1989. She had a son, Mikhail, in September 1990.