SwanQueen is a Femslash Ship between Emma Swan and Regina Mills from Once Upon A Time.
In Seasons 1 and 2, Emma and Regina were enemies fighting over custody of Henry. In later seasons, they became allies in order to fight various villains such as Zelena, Hades, and, in season 6, Regina's evil half, the Evil Queen. Said evil half came about via a Jekyll-and-Hyde split.
Swan Queen is not canon as both characters have partners.
Swan Queen is not a real relationship.
Both Outlaw Queen and Captain Swan are Canon.
Captain Swan are married as of Season 6 Episode 20, The Song in Your Heart.
Sadly, Robin died in Season 5 Episode 21, Last Rites.