[Nazir's]

I'd suggest your first step begin with building a case. Save all of those harassing e-mails and PMs, put your adoption contract along with them, anything, and everything else that you may think of. Contact the Better Business Bureau in her town and file a complaint! Hopefully, that alone will get her to wake up, as they will only mediate an issue in attempt to get you what you request-- which at this point is just for her to leave you the heck alone.

If all else fails, you'd have further built your case with a paper trail to follow. That will most certainly work in your favor. Then, take her crazy self to court and sue her for any and everything that you can (i.e. breech of agreement, harassment, sales while falsifying information--intent, mental anguish. etc..) A lawyer may be helpful in such a case but prior to hiring an attorney contact your legal aid department to obtain all of the information that you can. After doing so, you may find that you're confident enough to handle your own case. Look into the consumer protection laws in your state and the seller’s (if the sale took place in a different state).

IMO, you have not a thing to worry about. Unless your proven by the courts to be an unfit pet owner, there is no way that she can legally obtain the bird back without your permission. The sad part (which in this case works in your favor) is that there are not many laws to protect companion pets. However, you as the consumer have more right in this situation and laws which will protect you. You’ll go further.

The previous owners are of no issue or concern. They relinquished their bird and all right to it when they handed it over to a rescue, granted the bird was handed over. Obviously, this lady (the seller) knows that she should be more worried than you. She knows that she lacks the rights to do anything which is why she figures or is hoping that the previous owners can. Further, unless that rescue was legally handed over to her (which I doubt by her threats of getting previous owners involved), technically and legally she can’t do anything! Basically, she'd only be digging herself a deeper ditch for herself by continuing with her madness. She is doing business illegally, was not and still is not being forthcoming.

I would just laugh at her and ignore her because it all just sounds ignorant to me. Well, that’s not exactly what I’d do but it would certainly be the best thing to do.
Pity on her—She’ll get over it!