I worry about child’s cooperation (7)
I believe the answer is:
liaison
'cooperation' is the definition.
(I've seen this before)
'i worry about child's' is the wordplay.
'worry' becomes 'ail' (I've seen this before).
'about' shows that the letters should be reversed in order.
'child' becomes 'son' (male child).
'i'+'ail'='iail'
'iail' in reverse letter order is 'liai'.
'liai'+'son'='LIAISON'
(Other definitions for liaison that I've seen before include "Contact between groups" , "Co-operation; love affair" , "Mutual communication and co-operation" , "Connection - relationship" , "Cooperation between people or organisations" .)