Owner of a small % of an LLC. Given an Operating Agreement after it was started and money invested.Does my spouse have to sign the Operating Agreem?

Are you the owner of the interest in the llc, or are you and your wife jointly the owners?  Unless otherwise agreed in advance, someone now owns an interest in the llc; an operating agreement is not necessary for this to occur, and if there is no operating agreemtn, the terms will generally be set by state statute.  If you own the interest jointly with your wife, your wife's consent is required for the operating agreement to be valid, but the issue gets complicated if you indicated to the other llc members that you were acting for both your wife and yourself when you invested.  You may then have what is known as "apparent authority" to act for her vis a vis the other members, and your agreement may be binding on both of you, although your wife may be able to sue you for any damages she suffers due to your acting for her without her authorization to do so.  As I said, complicated, and there could be other issues as well.