HVV is expanding into Schleswig-Holstein and will be including four new counties. By default, student tickets cover the entire HVV area but because that area will be growing so much, they want to change hers to just Greater Hamburg [their area "Großbereich Hamburg"].
They've realigned the boundaries of some of the fare zones, especially in the south (where all fare zones outside of Greater Hamburg either merged with another zone inside the boundary or where the boundary just got moved to include the fare zone) and the east (where some fare zones got merged so that you don't travel through as many zones any longer).
But Tornesch, where my parents live, is still just outside the boundary of Greater Hamburg as it has been for years... so she'd have to pay extra to go there (which she does fairly frequently to tend to the garden there).
But a ticket for the complete area of HVV is more expensive (roughly €40 compared to €30 for just Greater Hamburg or €29 for what she pays now for the complete area), and there's no way to buy "Greater Hamburg + 1 zone" for a student ticket as there is for adults (I had that rate when I was still living with my parents but working full-time).
So now she's considering whether to accept the change to simply Greater Hamburg or maybe to give up her ticket entirely, since she doesn't take public transport that often over long distances; she reckons she could take the bike to school and for shopping, or even walk.
She already did that for a while before she got a student ticket, but she was rather glad when we decided to buy her a ticket again :) So we'll have to see.