I have had a good afternoon of painting the fish for my daughter. Progress can be seen in the following photos.
First I did another layer of the yellow and added some green.

Next step was to add some blue circles, and to be honest mess up the bit between tail and back fin by adding too much white and then some green. I was attempting some wiggly lines but the brush was too thick. But the joy of using acrylics is that once dry I can go over it again.

Silver paint added to the background and I do another layer of orange on the fish and call it a day.

I think that the painting bit is now done. Next step, another day, will be to add the fine details using a felt pen. I am a bit concerned that I have over-done the silver but I expect that will recede once I do a layer of felt pen over it. We will see.
Overall, I am very pleased with it. And my daughter has had updates via the phone and is also pleased with progress.