No, you don't need secure access to get information about children in the households. But note children under the age of 10 don't answer any questions themselves. 10-15 year olds answer some questions - see w_youth files. For 0-9 year olds, their parents answer questions about them such as their development, childcare arrangements etc.
w_indall files include all household members of responding households. So, it includes 0-9 year olds as well. You can get their age and sex information from this file. The identifiers of parents are also included in this file: fpid mpid w_fnpno w_mnpno w_mnspno w_mnspid w_fnspno w_fnspid. You can use these to attach information about the parents to that of the child.
Information about the children such as childcare arrangements, child development are available in separate files: w_child. In these files each row is for a child<16 years.
Information about the newborns are reported by their parents and this information is in the files w_newborn. In these files each row uniquely represents a parent-child combination, where pidp identifies the parent and then the w_newchno is the newborn number for that parent.
Please take a look at these files and the variables included in them.
Hope this helps. If you have further queries please let us know.
Best wishes,
Alita
Updated by 
Updated by 
Updated by Victoria Nolan