You can assign a disabler widget directly on the element you want to disable. The disabler plugin will act directly on the element and attempt to disable any child elements under the top element.
If the element that the disabler widget is initiated on does not have an ID attribute with positive length value, then the element will be ignored by the disabler widget. The labels in front of the input controls have ID's. The labels beside the checkboxes and radio buttons do not. Disabling the labels will not disable the labels without ID's.