[tomsem]

The older Kindles do not support Cloud Collections (for sure anything older than PW1 and maybe PW1 PW2?), you were able to import previously used ones, but then you had to one by one add items to them. If you family members have those, And you have something newer than PW3 then there will not be any collisions. You can do all the Cloud collection management on the newer Kindles (eg Voyage, KBasic8, PW3). On library Tap ALL to list all books. Then Tap FILTER. Collections will show at bottom of the options listed, you might need to scroll to it so you can tap on it. It will list all of the Cloud collections. tap and hold to Rename, Delete etc (or tap the 3dot menu to right of each).

Whether pre-cloud or not, you can delete any you don’t use.

The Kindle has a Term ‘download collection’. It’s not necessary, you can always add/remove items without having them appear all the time On home screen, and You can always toggle to ALL/CLOUD to see them listed (Using Filter) if you want to see them.

You can also turn off sync as well on the family kindles. That will keep reading position local to their device (and collections too I think). If that’s the only reading device they have then there’s not much reason to sync.

That said, Collections are pretty limited and Cumbersome and I use them sparingly: Current, Next, Favorites and that is about it. It’s no longer necessary to have one for Read, as that is now a property you can set per book.