Demo

This is 'b' element but it is not the first child.

This is the 'b' element and it is First child of parent div.

This is the first child of the parent 'p' and it is 'b' element.
This is the second child of the parent 'p' and it is also 'b' element.

This is the first child of the parent div in'b' element.
This is the second child of the parent div in 'b' element.

This is the first child of the parent div in 'p' element.

This is the second child of the parent div in 'p' element.

It will not work in IE9.