How long after you were convicted can you have a gun?
After you have received a pardon and are no longer a convicted felon.
A spouse of a convicted felon can certainly own a gun in any state. I would highly recommend that the gun is not kept anywhere where the convicted felon can have access to it (do not keep it in the same home, it would be best to store it at a gun club or similar). If the gun is kept where the felon can have access, it will be easy to claim that you had…
A convicted felon is generally prohibited from possessing a firearm of any type. If you have been convicted of a felony you maybe arrested for simply having a gun in the house. If you are awaiting trial, you may be forbidden from having a weapon by your release documents. If you were charged and not convicted then there is probably no restriction on owning or registering a gun.