Trying to murder the husband and failing in the process is as bad as murdering him, but if she never really tried to murder him but was falsely accused, then she probably do not deserve the prison sentence she was given for murder. If she do not deserve the sentence she served but ended up committing a crime (murder) that attract such sentence, she should still be given thesame sentence because the first sentence has somewhat proven that she actually murdered her husband or can murder her husband... since she already served the first sentence, an additional sentence can be given for the fact she is capable of murder which is as bad as murder itself. People are better of having her in isolation to keep the rest of the society safe from her until she is completely reformed for good.
She would only deserve compensation or justice for being falsely accused of murdering her husband if after regaining her freedom they later realized she was fully innocent or never commited such crime.
You are nolonger innocent once you have become guilty of the crime you were falsely accused of. Your past innocence will no longer be counted/remembered. And it means you actually deserved the first sentence you were given in innocence. This should help people understand that anyone who is capable of committing such crime doesn't really deserve to be called innocent. The evil  was either in her growing  or it was expressed in other ways like in words,thoughts etc. It's possible to murder with your words, and ofcourse thoughts