Marianne is still sick.
First she is ordinarily sick for a few days. Sick enough to need the apothecary (who is NOT a doctor; use of apothecaries was quite common in Austen's time). Sick enough to be contagious, so the Palmers decide to leave with their baby. That's right - they are leaving their own house.
Then she is seriously, distressingly sick for a couple of days. So sick that Colonel Brandon makes a run to Barton Cottage to fetch Mrs Dashwood. So sick that Mrs Jennings and even Elinor begin to worry she won't make it until Mrs Dashwood gets there.
Then she starts to get better.
And then Willoughby arrives.
I defy you not to turn the page.