This quote is from the end of chapter 38 in Pride and Prejudice. Elizabeth has just spent six weeks with Charlotte and Mr Collins. She is now considering whether she should tell Jane of what has happened with Mr Darcy.
"It was not without an effort, meanwhile, that she could wait even for Longbourn, before she told her sister of Mr. Darcy's proposals. To know that she had the power of revealing what would so exceedingly astonish Jane, and must, at the same time, so highly gratify whatever of her own vanity she had not yet been able to reason away, was such a temptation to openness as nothing could have conquered but the state of indecision in which she remained as to the extent of what she should communicate; and her fear, if she once entered on the subject, of being hurried into repeating something of Bingley which might only grieve her sister farther."
I think that life is full of these predicaments when you keep something from someone you love because you dont want to hurt them, only to later be blamed for not sharing information you knew. It is very hard to judge what is best in these situations. Overall I think honesty is always best and then everyone knows where they stand. Thankfully for Jane things worked out remarkably well in the end for her and Mr Bingley.
Pic: Elizabeth and Jane, Pride and Prejudice