Looks like it was total Hate Thy Nader drama ... 'cause Brooks went full block mode on her own sister after she unveiled her match with tennis ace Carlos Alcaraz.
Grace Nader spilled on the "Not Skinny But Not Fat" podcast -- saying Brooks didn’t just block her online, she straight-up iced her out in real life too ... all thanks to her loose lips about the new romance.
Grace says the sisters only patched things up when Brooks hit "The Andy Cohen Show" -- their publicist insisted Grace sit in the audience, and that’s when the ice finally melted.