I think it's made worse by her admitting that she did this deliberately.
It also casts a bad light on Kirk, or on her opinion of him.
But that's not the same thing as saying it makes her look like a complete idiot. That's what puzzles me. Saying it makes her look deceptive or devious, I could understand. But idiocy is just the opposite, isn't it? A complete idiot would be incapable of thinking deviously.
You are reading the 'idiot' too literally.
Perhaps it's best not to try and reconcile 1960s portrayals of women on TV with the tougher character of the movies.