Two year old grandaughter who has severe temper tandrums

My wife and I took our grandaughter out to eat in a very nice
restaurant and after sitting in her highchair she began to scream and
holler like she was in the worst pain of her life. She Had A Temper
Tandrum. I took her out of the restaurant and put her in the backseat
of the car and she proceeded with her tandrum on the floorboard of the
car while I stood next to the car waiting for her to finish her
tandrum while my wife packed up the remainder of the uneaten food in
the restaurant. I picked up the grandaughter off the floorboard for
fear that she might hurt herself and placed her in the carseat and
continued to wait hoping this ordeal would be over soon. Just before
my wife came out of the hospital this girl stopped he tandrum as
quickly as she had started it. The temper tandrum took a very long 20
minutes and all of the time I was wondering whether she might need
medication? After she had finished her tandrum she acted like nothing
had happened. The temper tandrums have gotten so bad that I told my
wife that this grandaughter would no longer be to live with us if she
did not stop with her negative behavior. My thinking is that our
grandaughter may need some psychiatric drug to slow her behavior. She
told me that the grandaughter is just a toddler and that I did know
raise children. I do not not know how much longer this will go on. O,
I forgot to say that this child is a very spoiled child.