After the CW's heavily watched CRISIS ON INFINITE EARTHS crossover, the showrunners made a point of merging the separate universes (SUPERGIRL had existed in a parallel Earth to FLASH and ARROW, largely because she originated as a CBS show before migrating to the CW). In current canon, the characters still believe there is now only one merged universe. But the viewers realize this is not the case, as multiple Earths were shown once more at the close of the event.
One of these Earths was Earth-2, originally the home of Jesse Quick and now the setting for the new CW series, STARGIRL, starring Brec Bassinger as young Courtney Whitmore who finds herself carrying on the legacy of a Justice Society of America hero. Whether or not this opens the door to Jesse Quick (Violett Beane) or her father, Harrison Wells (Tom Cavanagh) is anyone's guess, but we can keep our fingers crossed.