Hey Juliet,
I can thoroughly recommend the Thorn Voyager childback variants. Great fun to ride but highly dependable workhorses, mega stable even when junior suddenly starts gesticulating wildly at something in a field.
Have a look at St John Street Cycles which I think is Robin Thorn's outlet. If you like the sound of them, but don't fancy paying "new", we have two of them of different sizing & are looking to move them on as the bairns have graduated permanently to solos & garage space is always under pressure. We are near Wantage, Oxfordshire if that's within range for a test ride, or I can provide photos & pedigrees of our two machines....