
Brushing them everyday should be normal and as part of training.
I am a bit suprised that a pedigree Border would shed so much coat. Mind you most breeds don't shed a lot at that age even if they are breeds that are supposed to shed. Are you sure it is shedding or is the coat falling out?? I don't mean to alarm you but I am a bit alarmed myself.
I have asked the question on another post by you but I do find it a bit suprising the age you have been able to get this puppy at and that it is losing coat. Sounds like you have had it earlier that 6 weeks if you have had it a few days now and it is 6 weeks.
A smallish breed should be with it's mother until 7 1/2 weeks. Occasionally if they are mature 7 weeks is fine but no sooner. I know that I have bred or owned was mature enough to go before 7 1/2 weeks.