Widget Visibility for page's children

Hello,

I would connect two sidebars into one (it’s special sidebar with only Feature a Page Widget plugin).

I am using second on Presentation page and it’s page children (Presentation -> A, Presentation -> B) – I am including another sidebar template – and first on rest of website.
I would display it like for second’s items “Show if page or page’s parent = Presentation”, but it’s going to be some items here and I would make it easy for main redactor (administrator).

What trick could I do to give only one statement (without OR) to each widget?
Category and tag are gone, because it’s page, not post (I won’t install plugins just to able do it for pages).
Or there will be need to pull request with feature like checkbox when selected page has children, to specify to include them or not?

Greetings

https://wordpress.org/plugins/jetpack/