I think the key is finding something that lets the child know you mean business and ultimately stops the bad behavior. You will be able to tell if the punishment works if they stop doing whatever it is you are punishing them for (if she continues to come home week after week and is still talking and still having to write sentences----it's not working). You know what I mean? You have to figure out what works for your child.
I'm was an English teacher before having my girls, so I personally wouldn't do the sentence writing, but that doesn't mean it wouldn't work for someone else. I want my kids to like writing and not view it as a punishment. JMO.
My girls LOVE Hannah Montana (the tv show on Disney Channel). Since they don't get to watch a ton of tv, it is a big deal to them to see the show. I took it away once for bad behavior and it was a big enough disappointment that the problem stopped. Now I can say, if this happens again---you won't watch the new episode........blah, blah, blah. Hopefully you will be able to figure out what works for your daughter.