describing not analysing.
So it's not set questions, it's her choice, which is quite unusual.
There might be a clue here, if she is working hard, setting her own questions, but only getting a desmond (tutu) it might be worth considering whether she is picking careful questions, maybe ones that have been asked many times before, and then conscientiously providing a very full answer. That is a useful skill, and one she has demonstrated in A levels. Maybe she needs some more radical thinking to select the question and then more analysis of her material to present the key points to make her case
[ask me how i know, Im at work, multishirking when I ought to be writing an executive summary of the report i spent most of yesterday writing]
Having a discussion with a trusted tutor around this idea, if she can be brave enough to ask for more general feedback and act upon it, may help reveal what is going wrong.
If that just doesn't appeal, perhaps feels too unsafe, it may be worth cutting her losses and doing something else, saving the option for a funded degree for the time when she knows a bit more about herself and what she wants to do. Maybe TEFL or something light for a year or two. A higher apprenticeship might be ideal, but competition for places seems to be v v stiff
Before posting ive gone back to read the thread and notice that there is stacks of brilliant advice here. Ill add my own anyway. Degree classification very much does not correlate with career or even life success, but knowing there is something you are missing is always a horrible thought. The kind of skills required for success at Uni are very useful, whatever she chooses to do.
The presenting problem is already identified, you/she are researching possible solutions, finding and implementing the solution will be a boost to her self esteem what ever she chooses to do next. All the best
[back to my 'essay']