We're new to Motor-camping too. Even though we've spent several weekends in ours, we haven't actually driven it anywhere as a family yet...
(long story) but from the experience we've gained to date, even our family (mum & dad plus 2) in our 24ft camper can get cosy... if I had 4 kids... hmm.
The lads above are spot on, the layout is crucial. Trying to figure out how your family will get on
IN THE CAMPER, only you can tell...
For example, My daughter (11) has claimed the overcab double bed in our camper and she spends as much time as she can up there colouring, drawing and listening to music. My wife and I generally occupy the good size dining area at the back, one bench seat each on either side of the dining table. and my son (13) has his own table and 1 + 1/2 bench seat arrangement mid ships by the big window (you can see in my avatar). While we're living together in a confined "box", we still have a little space that each of us can call ours... this is good for our family. Of course when we sit down to eat or play cards as a family, we all sit together at the back of the camper at the dining table which is good for 4 to sit comfortably. Or better still, outside under the awning using deck chairs & camping table, the preferred option weather permitting of course.
So far this seems to work very well for us but being
green at this, we still have TONS to learn...
That might all go to sh*t later when we gain more experience...
But its all good fun and we love it!!