Ring is evidently the name of the Godalming estate.
The commentary on Lucy's appearance and how it changes over time is very interesting to me. This is before Dracula has arrived in England, so it cannot be caused by his feeding on her yet.
Is this Stoker establishing her baseline health, to explain why she gets so dire before anyone notices once Dracula does arrive? Or is this the supernatural influence of Dracula reaching across the sea and affecting her somehow, the same way it seems it might be causing her to sleepwalk.