I wasn’t being cruel, I made a joke. I also advised that your friend can check in with the first petitioner (if they are still in contact) to ask if they actually submitted the I-129f or of they withdrew. Maybe the best case scenario is that they didn’t file so she doesn’t have a pending petition.
On a more serious note, the timing and circumstances are a little unconventional (you call it unique as well). Your friend committed to marrying a US Citizen, that person decided to call off the engagement and 6 months later another US Citizen is ready to petition and your friend is ready to get married to them now. I know love works in mysterious ways, but that is a little concerning..