My french lops,sugar and spice

Here are some pics of my babies,they are house rabbits and have their own bedroom but come downstairs from tea time till we go to bed. They have got their own personalities already with sugar been the brave one who jumps on the couch etc.They are now 18 weeks old but they only weigh 4 1/2lbs and 5lbs although the gap is closing between the two of them,are they likely to still get big ?

My frenchie was bigger than our cats but i never weighted him, but your buns look very sweet