Hi, sorry to butt in, this is jus what my drama teacher's told me. She said that back in her old school, this happens every year, where there's a bad actor/actress and he or she is always not wanted int a grp. (and ppl get bitchy...and cry ..and fight etc etc) and those grps often ended up with the top marks.
She said one year, this girl was really timid and shy and the grp all hated her. They didn't shove her in any role and told her to do this and that, but they sorta discovered her abilities slowly. ie. she was a fantastic scribe and kept the grp in order and let everyone's ideas come through, developing from each other. Then they sorta realised she was good at movement, her tall figure and all and she ended up doing a fantastic performance without very much to say, but heaps of physical stuff depended on her.
Sorry to blab, i hope this helps. I know you're marked individually, but if only you stood out from the performance...then the marker would sorta get the vibe the grp didn't really work. I'm sure everyone has a person they wanna get rid of in their group, but it'll work out in the end!! (well..dats what they all say anyway haha)