There is no black and white rule on this, and it certainly varies depending on the attorney-client relationship. There are two basic principles, though, that are important.
First, you are the one that decides whether you will agree to a settlement. Your attorney cannot, and should not, make that decision for you.
Second, your attorney should be the one making the decisions about strategy and tactics to get to your goal. Certainly you should be able to provide input, but client