When leaving McNamara terminal you can catch the shuttle bus either in front of the Westin Hotel or in the "Ground Transportation Center" which is really level 4 of the parking garage. Remember AF does not transfer baggage to WN. So you get to carry it.

Then take bus to North Terminal which is about a 10 minute ride, check baggage at counter, then reclear security. Boarding time will be 6:55 pm - two hours after your intl flight arrives at a different terminal. I would not be comfortable taking family on this connection.