Can it be that Jane Austen in her state of deteriorating health is thinking back on happier days, when she visited Lyme, which she liked very much and where she was allowed to inhale the vigorating sea breeze and look out at the sea.

When one is ill one is also inclined to consider the seasons in one's own life. She's approaching her autumn even more than Anne Elliot. :-{
This sentence struck me as filled with longing and perhaps a hint of wistful hope....as all must linger and gaze on a first return to the sea, who ever deserve to look on it at all...