I do not think I would refer to it as anything other than a "Father Daughter" event. Just make sure in the body of the announcement, that the daughter, can invite one person to attend with her. Yes, of course it could be her mother, if no other man is in her life. Maybe a Grandfather, Uncle, God Father, etc..
Fathers get such limited opportunities to be recognized, honored and appreciated as it is.
And believe me, my parents were divorced and if I had my choice at the time, my mom would have been the person I would have invited.
You can call it a "sharing experience", "a coming together," "a gathering", "a celebration of a special bond". A way to have an important person in her life celebrate with her.