family reunion
US /ˈfæm.əl.i ˌriːˈjuː.ni.ən/
UK /ˈfæm.əl.i ˌriːˈjuː.ni.ən/

1.
a social gathering of members of the same family, especially after a period of separation
:
•
We're planning a big family reunion next summer.
•
The annual family reunion is always a joyous occasion.