Anakin, Obi-Wan, and Ahsoka were taken to a fulcrum outside the map. Time there is not a calendar. The Daughter died into Ahsoka; the Son and Father fell. Years later, Baylan Skoll stands on a statue of the Father on Peridea and looks toward a light. The beginning he wants may be this family, or the cycle they stand for. The series did not say. Filoni left the question on the horizon.
Mortis is not a third Order. The Ones are not a loot table. Do not file Abeloth as Canon. She is a labelled Legends theory until a film or show says otherwise.