Kids have picky habits on an off without even having to see a commercial. First explain that isn't a real girl but she is acting and that isn't even her real mommy...writing the company is a good idea but they aren't to blame, kids get picky. As parents all you can do is continue to offer healthy options, don't cook due to just what is their favorites and lessen snacks and treats before meals. You put it in front of her, explain this is what is for dinner and if she chooses not to eat, don't make a big deal out of it. Do not give her anything else and let her know she isn't going to get anything else until she eats it. Many a nights I have put dinner back in the fridge only two hours later having a child come to me hungry, I get the meal back out and tell them they need to eat dinner first then they can have something else. I don't force eating every single bite on their plates but I offer what I offer as a meal and they can eat it or be hungry, period. After a few nights of testing me, they are now at least willing to eat 70% of their meal.
The commercial is pointing out the norm in most kids with healthy food, just keep offering it and she will change her habits a million times. I know my kids eat healthy but what veggies they like changes month to month too. I try and have them choose a few nights a week what I make for dinner, other nights they help with the preparing process and some nights they complain, if they do, they can get down from the table, I am very matter of fact and if they want to eat later, it is in the fridge waiting for them! Good luck..it is normal