The only member of the house to have been mentioned is Ser Marwyn Belmore.
Burning shafts hissed upward, trailing tongues of fire. Scarecrow brothers tumbled down, black cloaks ablaze. "Snow," an eagle cried, as foemen scuttled up the ice like spiders. Jon was armored in black ice, but his blade burned red in his fist. As the dead men reached the top of the Wall he sent…
King Maekar I did NOT die in battle against one of King Aegon IV's bastard sons. That shoots down the theory that he died in battle against Bloodraven or Bittersteel.
The King of the Mummers probably will not make an appearence in AFfC but Harry the Heir might. It wil depend on where he decides to…