How about a B5M? They are cheap as chips these days, nearly indestructible, many spares are B6-compatible with small mods (that is, if B5-spares run out any time soon anyway) and if your daughter really enjoys it and gets hooked in a year or two, the car is even suitable/legal for competition
A cartoony car like the Lunchbox is fun (maybe even more fun to start with), but might prove quite fragile in the hands of a youngster: vintage suspension and gearbox, hard bodyshell... I am saying that without first hand experience though, so I could be wrong.