Hi I Have 2 Kids. Elder Is Daughter She Is

Hi
I have 2 kids. elder is daughter she is 7 year old and 1 n half month old son
My daughter is very talkative she is not writing anything in d class all time she is just taking. We r very much worried about her studies.
We punished her , tried to convince her for studies well but she is not doing.
What to do? Now situation is like she don't want to listen anything and even responding on our talk and all.