If children do not want to eat
My two half sisters (8 and 5 years old) ate very little and were also very small for their age. Once they wanted to brew a "knight's drink" with me, which they found together with their recipe in a children's book. So I helped them, but most of them did it alone ...
The drink tasted awful, but the girls still drank it and called it a "saucer," even though they blew their faces with each sip.
So I thought: you could even let the kids cook more often (of course, only under supervision) because if you think about what you could add to the dish and have helped yourself, you may eat it sooner.
So I sat down with you and thought about what we could cook. We decided on a vegetable lasagne and they were allowed to decide for themselves what to come in and lo and behold: Suddenly you can go inside.
P.S. Of course, this is not a permanent solution because it brews a lot of time and nerves.
