Complex sentence: She starts telling lies to Sudhir so as to meet Sunny daily, and gets so engrossed in love affair, that she forgets all her commitments as a wife and mother, and she realises that it is grossly wrong.
Split into simpler sentences: She starts telling lies to Sudhir so as to meet Sunny daily. She gets so engrossed in their affair that she forgets all her commitments as a wife and mother, and she realises that it is grossly wrong.