She likes to draw and has indicated she would prefer writing on her own topic for classroom journaling instead of what the teacher says. In class, she seems to have a hard time getting started then it goes downhill the more the teacher pushes her. Then the work comes home where she might put up a little resistance, but it usually gets done with little pain.
In my high school Spanish class the teachers explain that for our Oral Reports, we weren't allowed to do the 'Beethoven trick.'
She explained the some students memorized a few paragraphs about Beethoven, and then, no matter what the topic, showed of their speaking skills by relating back to what they had already memorized, no matter how off topic.
For example, if they were to talk about Airplanes, the Student might say: "There were no Airplanes at the time of Beethoven, Beethoven was born in ......"
So, one idea is to just talk to the teacher and find out what her objectives are for in class writing, and see if you can win permission for your DD to write on her own topics as long as she is doing X,Y, or Z.
If that doesn't work, practice totally wild and silly ways to segue from the teachers topic to your DD's favorite topic. My son seemed to like to write about anything as long as he could throw in a few jokes about cheese.
I'd also read the book: 6+1 writing traits because it puts learning to write in a totally different light than the 'copy edit' only approach I was taught with in elementary school. If you point out that she made an excellent word choice in her at home activities, that confidence will carry over to school. It sounds to me like your DD is worried that she won't 'do it right' for school. Is that part of it?
Grinity