Adhara stood on her spot after Rex left the master bedroom.
Even though she also wanted to eradicate the Supernatural for killing her mother, she can't hide the fact that the feeling becomes more substantial because the man that she loves is very determined to absolutely do anything to make that happen.
She saw the icy cold look on Rex's face just like an iceberg that froze his emotions.
The fact that Rosie is dead because of saving him definitely brings a sense of guilt, but more than that it also brings the feeling of helplessness. It's something far stronger especially for Rex knowing his backstory.
Without a doubt, the powerful emotions got the better of Rex.
It was so powerful that it beats the feeling of sadness that he felt from the fact that Rosie is dead, and subconsciously Adhara clenched her fists. She looks at the bed and feels that Rex is getting further and further away.