One year I managed to be in the same group as this nightmare of a girl for all 3 group tasks (3 person groups, same third person twice who was good, another third person who was good).
Task 1 : She didn't reply to emails or communications, didn't show up at arranged meetings, when she gave us her part of the presentation we basically had to re structure and re-write it all to make sense, during the presentation she got confused by her part and what she was actually meant to be talking about and the worst part of all is during the Q&A she was answering wrong then asked the panel if she could get her own flash drive and put up some more of her own slides... (also the other two of us knew the answer and her the slides she described weren't even close to relevant).
Task 2: During the planning stages she essentially acted the same as above. The during this presentation while in the middle of her part she decided her calculations were wrong (even though as a group we had checked them and decided as a group they were right), stopped in the middle, sat down with a pen and paper and started re-doing them (which there was no time for) and again faltered during the Q&A not being able to explain her part.
Task 3: This was half practical based half presentation, in this task 6 constituent tasks were divided between us, 2 each, based on work we'd previously done as a group. From that point on the paperwork and presentation were individual, the only group mark was the initial gathering of samples and organisation of tasks. It was just hard to watch her work and I am glad I wasn't marked with her. We were given 2 days a week for 12 weeks to do sample prep, analysis and interpretation, obviously weeks 1-2 were mostly prep then book instrumentation like 3 weeks in advance (30 people 1 of each instrument obviously lots of time constraints). By about week 7/8 this girl was still prepping slides, had about 200 by this point, and had not booked any instruments for analysis. On average most people had 20-40 slides and had analysed them by week 10. Again this didn't effect my grade but it was easily a task which could have been marked as a group in the end.
She ended up having to repeat the year and then dropping out I think, this was in year 3 out of 4 (Scottish Uni).