L.D.
Discipline her? No, she's only 9-months old and doing what every other 9-month old does at feeding time. Part of her learning experience is playing with her food. She's learning lessons about taste, texture, smell, gravity, velocity and the like. I think your expectations of her maybe a bit too high and not age appropriate. My children were definitely not feeding themselves with a spoon by the time they were 9-months old -- they depended on mom and dad to feed them or they fed themselves with their fingers. We would give them a spoon on occassion but it was more of a prop than anything and we always knew that there would be food all over them, the furniture and the floor by the time they were done.
To get a better idea what you can reasonably expect your child to be doing at 9-months, 12-months and so on, I would suggest you check out the following websites for information:
www.ivillage.com
www.parents.com
I didn't start disciplining my children until they were about 2-1/2 years old and only then it was for issues like like hitting or biting other children, not for control issues like they weren't feeding themselves properly. There are certain lessons in life you can't rush. For now, just relax and enjoy your baby. Feed her yourself with a spoon when you want her to eat or when you don't have a lot of time to clean up the mess, and allow her certain times during the day to play through exploration. The two of you will be better off for it.
Wishing you and your daughter all the best.