Yes they've tried counselling (and not elders...he isn't a JW anymore) but not enough sessions to help. I wish he would have stuck with the counsellor longer but felt it was going nowhere.
The goal of counselling isn't just getting couples back into a loving relationship but also, and it's sounding like this is the case, to easy any separation so channels of communication remain open. This is especially relevant here where kids are involved. I hope that the end result is your relative sorts out his problems and the family stays together but if he isn't expecting counselling to fix his relationship, approaching it as damage limitation may get him back to accepting professional advice.