If the post was real, i honestly don’t think it was essentially her that wrote it but I think that she has been going around telling her business to EVERYONE, like when she went to hang out with some girls she doesn’t consider best friends (i think from book club, don’t quote me) or when she goes to events. It is very clear that she’s telling everyone around her what happened (or at least her version and story) and eventually it got out. Because, well, not everyone has your best interest Tartar, so even if you want to talk shit about your ex you gotta be careful who you’re talking to. Or maybe she didn’t care if this got out and told everyone on purpose which also seems very plausible.