It’s happened in the last year. A levels all moving back to a linear course with no AS halfway through (you can study an AS as a stand alone qualification bit it doesn’t carry through into year 13 like before).
There is additional rigour and content in a lot of the new syllabuses and the general consensus is 4 is too much now.
We are allowing all of our students to do 3 with the possibility of doing further maths as a 4th but as an enrichment course with only 3 hours of timetables study.
Because students have typically gone for 4 at AS and dropped their weakest one at the end of year 12 we are used to students doing 4. However if you think back to 18 years ago before AS was introduced then people mostly only took 3 A levels…the universities will probably only look at their best 3 in 2 years time anyway.
My advice as an experienced teacher would be to take 3 and really focus her time on them rather than spreading it across 4. But I don’t know her and she could be very academic and hard working in which case 4 could be ok.
We only have one student in our lower sixth doing 4 this year.
Hope that helps