Describe, in your own words, why elinor was upset with people spreading the rumor that marianne and willoughby had
an engagement. your answer should be at least one hundred words.

Elinor was upset was because there was no factual or formal engagement between Marianne and John Willoughby.  She had not seen any confirmation of any kind other than how affectionate they were when around each other.

If there was in fact not any engagement the effect on Marriage could be devastating to her mentality, and her sensibility. She is social with her insightful and quite unrestrained that the prospect of her dealing with no engagement could be extremely detrimental to her well being. Elinor is also not one to gossip or spread rumors so this is quite concerning for her.

it was a big part of the story, making a lot of plot points happen?

the answer is definitely the first answer: lizabeth is older now and realizes that she may not have made the best decisions.