s represent the
non-NA entries in Edwards' table.
</p>

<dl>
<dt><code>boys</code></dt><dd><p>number of boys in the family, <code>0:12</code></p>
</dd>
<dt><code>girls</code></dt><dd><p>number of girls in the family, <code>0:12</code></p>
</dd>
<dt><code>size</code></dt><dd><p>family size: <code>boys+girls</code></p>
</dd>
<dt><code>Freq</code></dt><dd><p>number of families with this sex composition</p>
</dd>
</dl>



<h3>Details</h3>

<p>The data on family composition was available because, on the birth of