This actress appears in few episodes of this flick but she's a rememberable one. Still don't know who it may be.

She's CLEARLY not Ng Yee-San mentioned in the main cast.

The "dream-wandering" nurse from the beginning? It's very unlikely that she was credited even in the original version. Most of the people in this movie are either Shaw or TVB actors, so you might have some luck if you search for her with that in mind.

This movie could definitely benefit from a cast gallery. I'm calling dibs on it unless someone else has already started making one.