There is plenty of room for one adult + luggage or one adult and less luggage and a child. Child seat (optional equipment) will fit a child up to six years or 22 kg (whatever comes first). For bringing more than one child, you can add a trailer hitch (optional equipment) for attaching a bicycle trailer.
If not bringing any child (and child seat), Frikar ebike has approx 160 litres of luggage space (so our current vehicle is also a small cargo bike).