My husbands account is also showing my Bookmarks, how can I disable? All my bookmarks are also on my husbands user page, I would like to remove them and read one question as to sign out of my Apple ID when in his account but its asking me if I want to make a copy otherwise all my data will be removed from this mac but will still be available on my other devices .... I just daren’t risk losing everything on the mac either in my user page or his ... has anyone come across this problem and how did you solve it ?
You shouldn't be using the same Apple ID for two different people, so ideally yes you should sign out of the Apple ID entirely and create a separate one.

If you still wish to use the same Apple ID, you can just disable Safari sync by opening System Preferences → iCloud and disabling Safari.