Scheduling and managing events using Outlook.com calendar
In case somebody did not get it, if you try to add a new entry and don't have the option of choosing personal or family Calender, or if you don't see family calendars, you have to choose the circular icon on the top left of the calendar view, this could contain your profile picture, then scroll down and select "your family".
See Adams picture for referance.
For some reason this was disabled at some point for me, and had to be activated again.