So anyone who's read about Greek Mythology probably knows that Athena is a virgin goddess-and Ancient Greeks considered marriage and children as losing your virginity.
Ancient Greek were also taken very seriously. In fact, if you lose your virginity whether consensual or not, you were executed. Even MoA says this-you die in a horrible way if you lose your virginity, which is why the Romans ignored Annabeth so much.
So............Athena did not need to have children. Even brain children formed from her's and her lover's thoughts, because they're still children.
But! you say. But Annabeth!
Uh, let me speak, please. Some silence is required. Yes, thank you.
ANNABETH SHOULD'VE BEEN ATHENA'S CHOSEN, HER CHAMPION, NOT HER CHILD.
Let me explain about this.
So, Athena fell in love with Frederick, right?
Well, let's change it to she platonically liked Frederick and was impressed with his intelligence and wit, so she told him and his wife that as a gift, she could bless their daughter Annabeth with demigod powers, a chosen champion of Athena-
but she warns them of all the risks that'll happen, and tells them that Annabeth will be turned into a demigod directly, and she tells them how to raise Annabeth in the right environment.
And have Annabeth's parents be thrilled because both of them can fully see through the Mist. And honestly, they didn't think that it would be so hard to raise a demigod!
And once Annabeth is blessed, they keep pushing her-they think that she should be smart enough, but they don't put her in a proper environment for all of this because they're unable to get one because 1) It would be difficult to get tons of books in Ancient Greek
2) They didn't realise the actual consequences of having a child with ADHD and dyslexia because they were too excited with Annabeth becoming 'magical' as they put it, so they thought that she'd be insanely smart even though Athena warned them against this, and they keep pushing her, they're disappointed that she's not in middle school by only seven years old.
3) And by then, the monsters start coming and the spiders start coming too and they realise how difficult it is so they blame her for it.
And so she runs away and then everything else happens, and Athena feels guilty and angry about making Annabeth her champion when she was just an infant, so she guides her and helps her.
And then Annabeth could be isolated at camp without anyone in her cabin, because Athena's demigods aren't 'real' demigods-they have two mortal parents and are only blessed by Athena, so the camp doesn't treat them like demigods and kind of looks down on them.
So Annabeth feels the need to prove herself and this also makes her cling to Luke more. Also, she finally finds a real friend in Percy, which makes more sense, because how come she just makes friends with a random guy at camp, even a son of the Big 3, when she's been there for 5 years?
This makes Annabeth more relatable because there are people who's parents didn't think twice before having children and there are people whose parents pressure them academically too much.
And now you're probably wondering about Malcolm.
Yeah, what about Malcolm?
He's barely there in the original PJO series. Once in BOTL where he walks in on Percabeth hugging? Well, have another demigod walk in for another purpose.
Malcolm in TLO? Change it to another cabin. Simple.
BOO when he's attending the meeting? Have it be Clarisse.
TON when Apollo interacts with him? Have it be an Ares camper (Sherman Yang, maybe) who's gathering information, because Ares campers aren't just violent dickheads, they can gather information too. Information gathering is a part of war, and Ares campers don't just fight.
When he's mentioned coming out as gay because of Nico? Put another camper there. Whichever one you want.
Malcolm Pace lovers, I'm sorry about dissing Malcolm-I don't hate him, it's just that he's not even that important. If you took all the children of Athena (ruling out the historical ones which can be cut out) then Annabeth Chase is more important than all the other three combined. I'm not even sure if Zane is canon or not.