She was very decisive, indeed ! That could be interesting : Marie-Antoinette as real queen, just like her mother. With, as she said : "this blood running in her veins". She could do fine !
On the contrary, being so powerless may get on her nerves, she was so energetic... The only fields Louis gave her to experience her power were "menus plaisirs". It's not surprising that, in those conditions, she focused so much on pleasures !
Once, she became a true queen, with a true power... in her little empire of trianon. And in Saint-Cloud, too, she almost created. "De par la reine" !