I tried to add text after the first children, without success
<a href="#" name="usernameMenu" class="dropdown-toggle" data-toggle="dropdown" role="button">
<span class="glyphicon glyphicon-user"></span>add text here
<span class="caret"></span>
</a>
I tried some command.
My last one
$('a[name="usernameMenu"] span:eq(0)').after().append("add text here");
I get
<a href="#" name="usernameMenu" class="dropdown-toggle" data-toggle="dropdown" role="button">
<span class="glyphicon glyphicon-user">add text here</span>
<span class="caret"></span>
</a>