Methinks that if we do have a Red Wedding situation, it'll play out like this:
Angelina is in Constantinople, either willingly or unwillingly.
The Senators will be debating the merits of her views, potential compromises, etc, etc.
Then, all the Senators who have been vehemently against any compromise with Angelina get letters telling them to all go to one corner.
Suddenly, on the balcony, crossbowmen appear and slaughter every Senator who supported compromise, or god forbid, agreed with Angelina on anything.
The Emperor will then have Angelina killed, and this insignificant rebellion crushed.