You don`t say what type or sized van your Sister drives,not all vans are restricted by Law,even though they belong to a haulage company.
If I was her, I would continue to keep BOTH jobs running. Certainly wouldn’t take a substantial dip in my income just to pacify some europratt in Brussels.
Rules and regulations don’t make for a safer driver on the roads. Just observe the endless ‘professional’ numpty’s that keep hitting bridges, losing loads and riding on the limiter in thick fog banks. 
Best bit about being on 3.5 tonners, can just get the job done.
I usually bang mine out in about 7 hours, a 45 break half way through would just be annoying. And as for log books and so on, one of our drivers does it to bloody stupid details, but he has a digi too. I don’t bother and don’t intend to.