The moment Hal had stepped into the hall, Elenor had gotten the answer to the presence she had felt. The presence was Hal's and her unease only increased once she had made sure of this.
The fact that it took seeing him face to face for her to ascertain that it was his presence she had felt was worrying.
He had been outside her door and she had basically been blind.
The hall cleared out with someone picking Gregor off the ground to escort him out of the hall.
Phaedra was the last one out of the hall and before she got out, Hal pulled her toward himself and locked his lips with hers right in front of Elenor's unbothered face.
Phaedra resisted him a bit at the realization that she was not alone with him.
The fact that the double doors were closed and no one outside would be able to see them made her a little more relaxed but the fact that her sister was witness to this illicit act of hers had her attempting to pull away.