@twojaythomo @nigel has three buggys he connects together and a bike trailer for the littlest. The bike trailer would be too small for a 6 yr old so you would need a second buggy to attach to yours. Nigel has an assortment of ways of attaching them which he can explain later. At the front he has his GT followed by his Libre (5 yr old gets this one so his feet don't accidently drop down at speed), attached to the Libre is the PL comp with a bike trailer attached to the back.
You will also need some decent goggles or at a minimum sun glasses for your passenger as a fair bit of sand gets flung onto your passenger and you want them to be comfortable so they enjoy the ride. Our kids use their bike helmets but I like my full face one as it keeps out the flying bits of sand.
There is a pic of the buggys all connected in the meets/events forum under Sandy Point summer 17/18 on the last page of the thread and if you zoom in you can see some of the connections