Annabeth became extermely bitter of the way Athena treated her when she gave her coin to follow the Mark. Think about Athena is the whole reason she and Percy fell into Tartarus, if Annabeth hadn't had retrieve that statue she wouldn't have been near Tartarus.
At the celebration of winning the Giant War, Annabeth did two things.
First she turned to Athena and said, "You hate not knowing, so I am going to tell what I am thinking. Honestly an Olive Tree isn't that good. It would have been way cooler if you invented pizza or something." All the gods and demigods, except Athena, started roaring, Poseidon fell right off his throne and started rolling on the floor, knowing that Percy had said that to Annabeth a while ago.
Then Annabeth turn to Hera, "You are a bitch, you have made my life a living hell, and trust me, I have been there. You sent me frickin cow poo, and THEN you stole my boyfriend and his memory. I can't believe you have the audacity to call yourself the goddess of family. Yeah, goddess of family my ass. Fuck you." Everyone was shocked by Annabeth's outburst. No one ever heard Annabeth swear.
"I think you are-" Hera began.
"I don't give a hot wet monkey's ass what you think." Annabeth said.
"You have made a bad enemy today." Hera spat.
"What is the worst you can do, send more cow poo?"
"Hera, calm down." Zeus said, it didn't work.
"WHO DO YOU THINK YPU ARE TRYING TO GET ME TO CALM DOWN? YOU FO AND HAVE FLINGS EVERY NIGHT WITH A DIFFERENT WOMAN!"
"Hera, please." Poseidon said. Poseidon, being her favorite brother, calmed her down.
Annabeth was very proud of herself for standing up to the two goddesses she hated most.