She could be missing her chance to talk to him again by not confronting him directly, but Di's hoping to bring him in here with her. If she can lull him into approaching her on 'his' terms perhaps there will be less of a chance of him running again.

So she walks, keeping her eyes straight ahead. There is no one around here. Not this far out, not at this time of night, not in a sketchy underpass with graffiti decorating the walls.

When she's about halfway through she casts a glance backwards, disappointed to find nothing but emptiness. She stops and turns around fully, staring for a moment before sighing and leaning against the wall, arms folded behind her. She would wait just in case, but already disappointment was filling her. She should have just approached him herself. Hopefully there would be another chance soon.