I thought Elinor handled it the best she could at that moment. I don't think she was willfully trying to rain on anyone's parade, and it's sad that her mother is even trying to accuse her of doing so just to make herself feel better. In answer to her mother's question, "And now, Elinor, what have you to say?"

Elinor responded, "Nothing, for you have anticipated my answer."
It is as if Mrs. Dashwood is arguing with Elinor without Elinor's actual participation! I felt bad for Elinor at that moment. I can't imagine it feeling good to have one's own mother lashing out at you when you are as fearful as she is and want to act rightly to help improve the circumstances, not just to hope for the best.