parents involvement especially during a child's earliest years is the single biggest influence on their development, and achievements, as well as their overall behaviour and attendance. .
Also good quality home learning contributes more to children's intelligents and social development than parents occupation.
In case of Chiku, it is his parents duty to:-
understand their child's day-to-day progress
undertake family learning together
talk regularly with their child about their learning.
(Note: so all these is not Sona's job, so Renu and her husband should not blame her).