She will have just sat her AS mocks. These aren't "actual" exams, just practice.
You can sit AS exams still (for most subjects), and some schools enforce it (they cost the school extra money). She will get a grade and certificate for them if the school have chosen to pay for all students to sit them formally. The school however might not have in which case she would not be getting a grade and certificate. If she is sitting the exams formally, the results will come mid-August.
At the end of the two years she will sit her A2s. These will test her on the whole 2 years of content and overwrite her AS results. Her AS results (if she has sat them) will not contribute to this at all. These are what she will need for uni, etc.
I really wouldn't recommend her teaching herself. If she could have done it she already would have (as she did for GCSE). It's also quite a nightmare sorting things like the science practicals.
She needs to study as hard as she can now, and see how she does in the next set of exams. What does she want to do? Would she be happy graduating with Ds or does she want Bs or higher. If she only manages to get up to D knowledge at AS level she is unlikely to then get Bs or As in A2 level as whilst the AS levels no longer contribute to the grade, all the A2 topics learnt build upon the knowledge from AS level.
As for the dropping down to 2 A-levels, does she want to go to uni? As this will be tricky with only 2
My advice would be:
-Study hard now and see what she gets
-If she gets Es or lower resit the year
-If she gets D's and does NOT want to go to uni or grade dependent apprenticeship then continue to A2s
-If she gets D's and DOES want to go to uni or grade dependent apprenticeship then resist
-Sorry if this seems harsh but you also need to get more involved with her education, it's very uncommon for a parent to not know about the exams their child is sitting