dropsofvenus

there's going to be lots of other advice,
but for now,
the big thing you can do to protect yourself,
is
to withdraw the affadavit of support, form I-864, via postal letter back to the USCIS office that issued the receipt .
Since you've no receipt yet, you've no idea where to send the letter, as the address is in the receipt notice.
So, wait for that receipt notice, and then withdraw the I-864. Without the I-864, she won't be issued a green card.

Three posts violating the Terms of Service have been removed (personal attacks). I can appreciate the frustration people have when something like this happens but please do not resort to name calling and insulting each other in your frustration. If you can't post constructively, then do not post.
moderator hat off . . . .
greenivy, congratulations on your quick approval. Over my years here I have seen a few cases like this - and during my own visa journey there were a few instances. Upon investigation, it turns out that when USCIS is training new staff they will often just grab a petition/application from the most recent applications received that haven't yet made it to an adjudicator's desk. They aren't trying to circumvent the waiting time, just that those are the applications that are just coming up from the mail room and are readily available. It looks like they are training new adjudicators right now so there are going to be a number of petitions/applications processed quickly, and as we have a large membership here on Visa Journey, it is not surprising that some of these quick approvals will go to our members.
Is it fair? Nope. Is it frustrating? Absolutely. Is there anything you can do about it other than wish the beneficiary of this largess congratulations? Not likely. Many people - including me - have complained to USCIS about this over the years, and yet, it still happens.