She caused the brand alarm to go off to distract everyone while she secretly put her jewelry (or ordered Brock to do it) under Blair and her friends' pillows to accuse them of theft, so that Blair would not be able to attend the coronation ceremony and therefore, will not be able to make a claim for the throne, allowing Delancy to be princess.
yes.dame devan has acted.in princess charm school u can see that when the brand klok, bell rings the three vrienden left opened the door.and dame devan will go inside and hide her jewelleries.and she will tell that delancy saw her poking around her office