Siblings seeking refuge in Vallaki with a mysterious connection to Strahd

Siblings who had the party escort them safely to Vallaki in the wake of their fathers death. Ireena has been visited several time by Strahd, being left with bite marks on her neck come morning.
Ismark hopes to keep his sister safe in Vallaki, despite her stubborn attitude and habit of putting the well being of others before her own.
They have taken up residence in the Church of St. Andral, helping care for those who seek refuge from creatures of the night.