A.M.
Ha! Welcome to the World of raising a toddler. The good news is that eventually they grow out of it. You just have to be consistent with your punishment. My son doesn't make himself vomit but he throws things at me when he is having one of his tantrums. He does however like to gag himself with his fingers and paci, but not to the point where he throws up.
Right now I'm reading the Happiest Toddler on The Block. It seems very repetitive and I don't think I've learned anything from it yet other than talking "caveman". I tried it and my son looked at me like I was nuts. I wish there was some kind of Supernanny for hire in our area. It would be nice to have someone come for a weekend to discipline and train!
My advice about the vomit is next time, do not clean her up. I know this sounds awful but if you leave her in her vomit, she may be disgusted to the point where she won't do it anymore. As you said, she enjoys the attention she recieves from doing it, so you are going to have to use reverse psychology. Since you know the vomit may be coming, you may have to make her time out place somewhere that is not carpeted. Or put towels underneath her. Plan ahead!
And try not to go bonkers. Easier said than done I know. When they are good, they are SO good and you just love them so much...but when they are bad, they are SO bad! You may look into getting some help from a VERY PATIENT nanny or sitter for a few hours a day just so that you have a few hrs to decompress and recharge. Or try mothers day out or partime daycare. It well help her to develop her social skills and give mommy some quiet time so that you don't go bananas. Happy Moms have happy babies.