You are believing this woman’s story. She is a convicted felon. The provisional ballot clearly states that under penalty of law, you are stating that you are eligible to vote.
Felons know they can’t vote in most states, and the ballot probably also stated that on it.
If she honestly knew she wasn’t eligible and voted anyway, then that certainly deserves harsh punishment. I’d want to see the ballot itself or something else that proves intent to knowingly cast a fraudulent ballot.
Five years is a very serious punishment. I daresay there are many thousands of illegal aliens doing the same thing and walking away scot free. That doesn’t make it right, but if we’re going to seriously prosecute voter fraud, the law needs to be equally applied.