I only did super basic stuff with Budibase since I didn't need all its features, but I believe it does let you make workflows and automations. But unfortunately I couldn't tell you more about it specifically.

If you need something more complex than a form though, the only other thing I could personally recommend is something like a Kanboard (is on docker, and it has a docker compose file on the github). You can add family to it, they could make a card, and it has automations that you can setup and plugins. The only downside is that it's not the prettiest option, but it has plenty of functionality.

There's obviously many other suggestions from others, hope you find something that works for you and the family. And hey, maybe if you find something good, share it too! Would love to see what you come up with.