Hi Brendan,
Family Safety is a feature that limits your computer from the contents that are harmful to your children. Removing a member is possible. You can do this online or on Xbox one. In whatever way, you will need to manage this in your Microsoft account.
Since you have the authorization for the computer usage in your family, you can manage this feature by removing members. To do this, visit this link: Remove members from your Microsoft family for instructions.
Let us know if you need more help.