ELINOR DASHWOOD because Marianne needs her sister and closest confidant here. She can't possibly endure this without her and Willoughby. For Elinor's sake, EDWARD FERRARS, so he can finally escape his mother and sister's thumb and propse properly to Elinor.
She suspects COLONEL BRANDON would just bring the gathering down, but he does have more intelligence and taste than three quarters of the people she expects to meet at Summerview Park. Perhaps he can find a nurse here.