主干是:She hopes that when others rea that, maybe they would think twice before they throw garbage into the river.
中间she and her peers care enough to clean it up. enough to do sth 是一个固定的用法,比如说:he is capable enough to make the model plane 他有足够的能力去制作一架飞机模型.
翻译:她希望当人们读到那篇文章时,(文章就是)她和她的同事们给予足够的关注来清理它(这条河),可能他们会在把垃圾丢进河里前认真地考虑一下.
供参考.