I am not completely sure, but this is how I would order these events:Viola enters Orsino's court dressed as a male.Olivia asks Cesario about his parentage.Feste returns the ring to Cesario that Orsino had given to Olivia.Sebastian reveals to Antonio that he has a twin sister.Malvolio makes a fool of himself in front of Olivia.Antonio offers to take Cesario's place in the duel.
Hope this helps!
