Yes, it does sound like you are being introduced to the terrible 2's... Don't worry, my sister-in-law says they are just the trial run for horrible 3's.
:)
As my son started these around 19 months, and we are getting close to 21 months now... Here's my advice...
-Pick your battles
-remember 2 yr molars are a bear & that is sometimes why food sounds good, but then gets turned away
-try not to stress, because they will feel it
-they are only this little for a short time...
I try not to feed his tantrums with attention. Example: Last weekend he kept trying to play in the dishwasher as I was loading it. After redirection didn't work, I flicked his hand (you know, the middle & thumb flick). It didn't really hurt as much as it got my point across. He melted down instantly. I calmly talked him through it. Saying things like, I'm not going to comfort you for crying over my protecting you. You know better than to play in the dishwasher. This is for your safety. When the 2 min melt down ended, he hugged my leg - for which I gave him positive reinforcement, along with when he got into a cabinet - then closed it without taking anything out of it.
Good luck! And I hope she has a wonderful birthday!