You can define a global variable in your theme functions.php
global $mywidgets;
$mywidgets = false;
in your template part add
global $mywidgets;
$mywidgets = true;
and in your functions you can check if its set to true:
function my_function(){
global $mywidgets;
$mywidgets = true;
if ($mywidgets){
// YES Your template part is loaded
}else{
// NO Your template part is not loaded
}
}