Chick 6 doesn't seem to be getting fed at all by the parents and is still tiny so I'm going to start to feed it as if I'd pulled it for hand rearing and hopefully that will get it growing. As an experiment I tried taking out the 2 eldest for a couple of hours to see if the parents fed chick 6 then but they still ignored it.
If you're on my waiting list, chick 6 is a spare so as long as the other 5 make it (and I think that they will), you're guaranteed a chick.
You can also see how their beaks are starting to become the correct shape for a parrotlet.