Answer: There are total 7 Children in family where 4 are boys and 3 are girls.

So each boy has 3 sisters and 3 brothers.

And Each girl has 4 brothers and 2 sisters.

This makes both statements true which says Each boy in this family has as many sisters as brothers. Which is correct as each boy has 3 brothers and 3 sisters.

Other statement is Each girl has twice as many brothers as sisters. Which is again correct as each girl has 4 brothers and 2 sisters.