How to prevent access to family member's browsing and app activity on other devices?

Hi, I have recently subscriped to BitDefender Total Security and planning on letting other family members use it on other devices (can install BD on up to 5 devices total as part of the offer). However they are concerned that as the administrator I will have access to their browsing and app activity.
Is there a way to make browsing & app activity private on every device?