My take on the scene at graduation ("Georgie told me")

This won't make any sense unless you've seen the movie obviously, but I'm open to hearing anyone's interpretation. I was very very confused by the scene between Gracie and Elizabeth at the graduation, particularly when she says Georgie told her he told Elizabeth that his mom was molested by the brothers, and it was a lie. "We talk every day." It's a completely bizarre moment, because whether it's true or not, how would she know about that unless Georgie really *did* tell his mother that, regardless of whether or not they talk every day? Why would he do that? It's so improbably strange, yet there's no other way that she could possibly know.

I racked my brain trying to figure it out and here's what I came up with finally. Obviously, Georgie and Gracie do not have a good relationship at all, and while it's possible they talk or that he picked up if she reached out, I highly doubt he would confess that he told this story to Elizabeth. And yet she knows he did. My take is that it really did happen, and Georgie goes around telling this story to everyone he possibly can to humiliate Gracie. Joe indicated that he saw the two of them talking on the bench outside the restaurant, and she puts two and two together. She takes the chance of being wrong (when odds are he did indeed mention it as usual) in order to throw Elizabeth off balance and make her doubt the veracity of everything she witnessed, and it clearly worked.

I also noticed that Gracie insists Joe drive Elizabeth home even after she offers to walk; I doubt she wanted them to have sex (she thinks she has Joe too whipped) but it was so deliberate that I think the intention was to leave Elizabeth milling about the restaurant, where Georgie has a chance to find her and talk to her, or vice versa since she's so nosy, and the truth will out, thus giving her a chance at the upper hand in their last scene to control the narrative. Some have said Gracie probably molested her two younger brothers, but I think that's more of a binary internet/reddit reading of the material where people who do a bad or objectionable thing are all bad and completely irredeemable in their eyes. I think the story how she was molested herself probably was true, or true enough that it made her into who she is and into this regressed traumatized state that manipulates others rather than being a lifelong molester.

The rest of the scene is kind of obvious, when she says that insecure people are sad and that Elizabeth should get lost, implying that she knows she had sex with Joe, which was pretty obvious. The rest is more of a puzzlement but I get that it was a power move on Gracie's part, and the bigger point being, that Julianne's character was a better actress than she ever let on, far better than Natalie's character the "real actress," which she realizes in that moment. If the intent was to confuse this basic Hollywood airhead, it clearly worked and influenced her portrayal.