Whoa!! THis is typical 3 year old behavior!! They are learning constantly as well as testing out any ideas that cross their mind. My oldest is 6 and wanted to copy mommy n daddy. My Son is weeks from being 4 and still has his days when he wants to be the baby. Thats natural.
DO NOT WORRY BOUT SKIPPIN A MEAL!! Kids aren't goin to starve themselves. If she's really hungry, she will eat just bout anything you put in front of her! Children can be stubborn....they're children. Dont stress too much.
The character plastic ware is a good idea..anything to motivate. Try also telling her brother how big he is and how proud you are of him when he eats with silverware and then make sure you do the same anytime she exhibits the same behavior. She will want the same praise. If she doesn't want to eat, then let her sit there and be upset. If she outright won't and you send her to bed, tell her she can try again in the morning. She'll realize you dont give in and will soon enough forget all about being stubborn(on that issue...she'll find another one...lol)
My son doesn't like to stop moving long enough to sit and eat. BUt is ALWAYS "STARVING!" We require meals to be eaten at the table as a family and have had many times when he refuses to eat because he dont want to sit down to do it. He wants to take a bite and run and go back n forth. So he didnt get anything new to eat till he completed his lunch one day. No snacks, no dinner, nothing but water and his original lunch. Everytime he was "full" of his two bites - I put it up and 15 min. later when he was hungry, it was back. He didn't like that. He's always been a snacker. He eats constantly and is very lean and hyperactive. Even with healthy snacks, he needs his meals for proper nutrition. So for a full 8 hours he held out not eating because he was mad at me for not letting him snack and run around. When we all sat down to dinner - he got his saved lunch. He was upset but hungry so he ate it plus dinner items he wanted after. He generally finishes his meals nowadays.
Just hang in there!!
ps. mine now has come up with a "special" language and uses it to sass and answer me when he's not getting what he wants...there always something NEW!!! AHHHH!!!