The only person you should be asking is your lawyer.

No. You can only get a subpoena if there is an active lawsuit.

It's not "ok" for her to do this, but it isn't legally actionable either.

If the co-defendant killed someone, you could be looking at felony murder. Lawyer up immediately.

it could have just been a mistake. Either way, you have suffered no harm as a result, so I don't see anything to sue for.

Unless there was a reward offered, you can't get one.

I think it is a longshot, at best.....................

Same question for the third time. Same answers as before.

If you don't have an attorney, they probably won't settle, because they know you have no idea how to conduct a jury trial.

You already asked this. You can and will be sued.