Nevertheless, she might be mistaken.

It would be necessary to seek her acquaintance by some excuse and endeavour to draw from her some portion of her story, enough to confirm Unorna's suspicions, or to prove conclusively that they were unfounded.

To do this, Unorna herself needed all her strength and coolness, and she was glad when a lay sister entered the room bringing her evening meal.
There were moments when Unorna, in favourable circumstances, was able to sink into the so-called state of second sight, by an act of volition, and she wished now that she could close her eyes and see the face of the woman who was only separated from her by two or three walls.

But that was not possible in this case.

To be successful she would have needed some sort of guiding thread, or she must have already known the person she wished to see.