If a relative/friend filed for !-864 for my wife, what are her chances of getting her visa?

If you submit the joint affidavit of support that satisfies the income requirements you should be fine.

If the person who filed the I-864 completed all the paperwork and their income/assets are sufficient, then it should be approvable, if that was the only issue waiting to be resolved.

The I-864 is the affidavit of support with which you as petitioner for your wife assure CIS that she is given a green card, your wife will not end up on welfare. Where you do not make enough money to convince CIS, you can ask a friend or relative to join you and file an affidavit of co-sponsor where the co-sponsor contracts with CIS that s/he will be jointly responsible for your wife not going on welfare. The co-sponsor must be either a US citizen or green card holder [illegal aliens are not allowed]. If your co-sponsor's income satisfies CIS, there will be no problem and your wife will get her green card.

The visa should be issued if the co-sponsor's affidavit is adequate.

Hopefully they will approve it. If they don't, come see me if you want a lawyer to fight for you to get it.

If the co-sponsor has enough income and/or assets to help you, then the application should be approved. You should consult an immigration attorney and/or the poverty guidelines on the I-864 webpage.