That is... mostly what she means. Also, Heather doesn't think that Harrison would be able to come here, not with the demon Focalor inhabiting his body. They have demons aplenty here.

She does not speak just yet. She is always suppressing the mesmerizing quality of her voice when she speaks, and with the memory of facing the thing within Harrison brought to the forefront of her mind, Heather's control is weak. It would not be safe to speak.

She nods, and turns her face away from Sephiroth.