I am not sure you should. Young lawyers have to be very focussed.
If being a lawyer is what he wants, then he has to hit the books. He needs to argue and discuss with other arrogant young people. He needs stress and adrenalin.
There are a few individuals who are serene and content being lawyers, but that normally only happens about 10 years after qualifying - if it happens at all.
During exam and term paper time don't bug him with your personal needs and wanting to show support. Go visit your sister and come back after the exams.
When he has nothing else to do he will have time for you.
I am afraid a lot of lawyers end up divorced - and we cannot work out why.