Hello Julie,
welcome to WikiTree.
On WikiTree there is no "my WikiTree" and "your WikiTree".
Every person should get exactly one unique profile – ideally.
If you add person 2 as mother of person 1 and I add person 3 as father of person 2, than automatically person 3 is the grandfather of person 1.
If you want to check the profiles, you need to create your own check list after your requirements. There you set the status of profiles of your interest as checked or unchecked.
If you find a profile with issues in your eyes, you can do more research and correct them or learn that it was correct.