A common complaint in Facebook genealogy groups is somebody incorrectly added a family or family member to a tree where they don’t belong. My suggestion is to accept and realize you have no control on sites where anybody can create a tree (Ancestry, MyHeritage, and similar sites). It will save you a world of grief, aggravation, and frustration. Contrary to claims to the otherwise, nobody and I mean nobody, has a perfect tree on any genealogy site. The more people in your tree, the greater the likelihood that you have mistakes in your tree due to Not the Parent(s) Expected (NPE) being in the mix numerous times. That doesn’t include the numerous births that weren’t recorded for children who died young. My great-grandfather’s sister had a child who died ten (10) days after he was born. Many trees don’t list him as the tree creators were not aware of his birth and death.
Before I dive headlong into this topic, I will differentiate between two types of trees used by different sites. Ancestry, MyHeritage, and many other sites allow you to create one or more trees that only you can modify. However, you can add contributors and editors who you give whatever level of access and control you want, including the ability to edit, add, delete, or otherwise change.The second type of tree is something FamilySearch, WikiTree, and a handful of other sites use. It’s a One Tree family tree. By that, I mean, there is only one me on that tree. There is only one you on that tree. How much control others have on modifying it depends on the site as some sites allow you to add people who can modify the people you added to the site. However, the sites tend to allow admins, moderators, and arbitrators the ability to override your decision. If somebody decided I was born in Gulfport, Florida instead of Gulfport, Mississippi, then if they convinced The Powers That Be (TPTB), my birthplace would be incorrectly changed to Florida even though I have a Birth Certificate that shows Mississippi. I have seen enough complaints about WikiTree and FamilySearch that it happens a lot more often than people like.
For example, on Ancestry, I gave my daughter full control on my/our tree so she can add to, delete, modify, and otherwise change everything on the tree. I consider the tree to be our tree as she will eventually inherit it whether or not she does anything with it. It stopped being my tree the minute she was born. She is free to do whatever she wants with it.