CKEditor font size

I'm using CKEditor and would like to customize my editor. When opened, by default it would already come with Arial font size 20 for example. In my searches (between several others , and other , and other , etc ...), I found ways to change the setting for TODOS editors (or create a gambi in the configuration file for a specific one) , but I I would like to make such a change only to a specific editor in a beautiful way with JQuery. I have the following:

 $("#MeuEditor").ckeditor({
      height: 350,

      // Isso não Funciona:
      font_defaultLabel: 'Arial',
      fontSize_defaultLabel : '20'
  });

No one knows how to solve this?