I know people have a mixed reaction to LR and how she "advised" Anne to break off the engagemend with Wenworth. However, I think in Ch. 5 we see another example of her true affection for Anne and how she knows the workings of SW and E though she is still surprised.

Lady Russell, convinced that Anne would not be allowed to be of any use, or any importance, in the choice of the house which they were going to secure, was very unwilling to have her hurried away so soon, and wanted to make it possible for her to stay behind, till she might convey her to Bath herself after Christmas

LR knows now how little Anne is appreciated at home and very much wants to be able to spend time with her. Why subject Anne to more loneliness?

So far all was perfectly right; but Lady Russell was almost startled by the wrong of one part of the Kellynch Hall plan, when it burst on her, which was, Mrs. Clay's being engaged to go to Bath with Sir Walter and Elizabeth, as a most important and valuable assistant to the latter in all the business before her. Lady Russell was extremely sorry that such a measure should have been resorted to at all -- wondered, grieved, and feared; and the affront it contained to Anne, in Mrs. Clay's being of so much use, while Anne could be of none, was a very sore aggravation.

Anne herself was become hardened to such affronts;

I'm confused by "almost startled" bit. Does this mean that she learned of this in company with SW and E and had to cover up her feelings? Or does it mean that she was surprised but then realized who she was dealing with?