Complex sentence: They consummate their relationship, and Uttara then slowly starts taking control of Devyani's household activities and by the time she is fully in charge, no member of the family realizes any difference, except Priya and Devyani.
Split into simpler sentences: They consummate their relationship, and Uttara then slowly starts taking control of Devyani's household activities. By the time she is fully in charge, no family members realize any difference, except Priya and Devyani.