Weaning should begin when the babies are six weeks old, every two days dont bring them out for a feeding. It is best to keep the babies in a seperate cage and bring them to mom bunny once a day for their feedings. When the babies are 7 weeks old take them to mom about every three days, gradually stretching the time they don’t get their mother’s milk a little more each week. When the babies are eight weeks old they should be fully weaned. When seperating the babies from their mom at six week be sure to offer fresh feed and water along with hey. As weaing is very stressful on a baby rabbit. Your three week old babys should stay with mom or go out each day for a feeding until they are 6 weeks old.
Dad should not be kept in the cage with the babies. He is probably stressing mom out very much right now and he could harm the babies, with most males any rabbits that moves is something to breed with. I STRONGLY encourage you to move him to his own cage.
I am worried about you keeping the mom and dad together, there is a VERY strong chance that mom is pregnant again, and if she has another litter in four weeks, she will kick her older babies out of the nest and only take care of the new ones. Please IMMEDIATLY remove the male from the cage.