Every single claims adjustor and every single insurance company will be different. Trust your lawyer to move this along. One of the best parts of a contingent fee arrangement is that the lawyer is also trying to resolve the case as soon as possible to be paid.
The above is general legal and business analysis. It is not "legal advise" but analysis, and different lawyers may analyse this matter differently, especially if there are additional facts not reflected in the question. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in California. See also avvo.com terms and conditions item 9, incorporated as if it was reprinted here.
Your state may impose time limits within which the insurance company must respond. Additionally, the attorney may have included a time frame in the letter. You should consider speaking with your attorney about when he or she expects the insurance company to respond and what state laws, if any, apply in this case.
Any answers are intended for informational purposes only. The answers are not intended to be, nor should they be interpreted as, legal advice or opinion. The reader should not consider this information to be an invitation to an attorney client relationship, should not rely on information presented here for any purpose, and should always seek the legal advice of counsel in the appropriate jurisdiction. Transmission and receipt of the information in this answer and/or communication with this law firm is not intended to solicit or create, and does not create, an attorney-client relationship between the Law Firm and any person or entity.