J.H.
You might try a pre-test with her. On Monday you test her on the list. If she gets all correct you will only review with her on Thursday. If she misses any you will study daily the ones she misses and review all of them on Thursday. It sounds like she doesn't want to admit she is having trouble and perhaps this will help give her more control.
I am not a big fan of copying the words as most will tune out what they are doing. I use to have my students make rainbow word - using a different color each time, or use letter stamps to stamp out the words. We also made boxes that showed the shape of the letters in the words - for a word like long you would have a tall box on the line, two small boxes and end with a long box going below the line. It helps kids to see the shapes. Do the words have a pattern to them? Many times they do, but the students may not see the pattern. I like the idea of spelling as cheer.
Remember rewards have more impact at times than punishment. It sounds like she needs her confidence built. You might try to reward her for doing better. If she gets 3 more correct next week (even if it is failing) she gets _________. Or, you may try to build a "bank" of correct spelling words and when her bank reaches say 10 words (or 20, you want it to be attainable in a couple of weeks the first time)she will get to ________. The reward doesn't have to be a money or gift award. It could be having a friend over for the night or painting her nails.
If she is having trouble in other academic areas, especially reading, you might wish to conference with her teacher.
Good luck!