One search a day

The deck tries to exploit Mandy's ability, so you need to get a solid searcher, which means Old Book of Lore, or temporary substitutes that allow searching for it (Mr. "Rook", Research Librarian). I found that enough but if you don't manage feel free to add Eureka! and No Stone Unturned.

Mulligan for Old Book of Lore, in the classic style of her library's friend Daisy Walker, although you'll be fine if you draw Mr. "Rook", probably in 3 turns you'll dig to the book.

You will most of the time go for an additional target of the search, not for searching additional cards. Only when you fill your hand (it means 5 cards as a rule of thumb, if you don't plan to play more cards before your turn ends) you can go for the +3 cards search, and if you're in a comfy situation you can go with Mr. "Rook" to a 12 card search to get rid of Shocking Discovery. Also deep digging is good if you are eager of resources (Astounding Revelation), or clue picking (Occult Evidence), or maybe blood thirsty (Blood-Rite))

So much knowledge

Once the searcher is ready, you will get 2/3 cards with an action (the 3rd being Astounding Revelation or Occult Evidence), plus the automatic draw at the end of the turn, it makes 3/4 cards. In 10 turns you empty the deck, so that's why to use a 50 cards deck. It gives much less weakness draw chance (6% with 30 cards, 3.6% with 50), and possibly not taking the 1 horror for emptying the deck.

As the card drawing is high, you will get basically whatever you need soon, and you can use the +20 cards for toolboxing.

The toolbox

Rather than putting a lot of fancy cards in there, I used the +20 cards to make sure you get the same chances of getting resources (Crack the Case in addition to Emergency Cache), protection (Deny Existence in addition of Ward of Protection) and ability boost (Unexpected Courage to back up Perception and Guts).

I put some 'fancy' cards as Tooth of Eztli (to profit the accesory slot), Fieldwork, Astral Travel (much more useful that it looks), Persuasion (horrible card, but we have to deal with enemies, see below), and Curiosity (really good if you manage a consistent 7 hand).

Not a fighter

is not our strength. Who cares about fighting when we know we are dealing with so superior cosmic forces? We use our Mind over Matter to have our plans done ("I've got a plan!") or to draw our sketches (Anatomical Diagrams). Some books may help too (Occult Lexicon). Although Persuasion is not the best card, I'm starting to like it, in the end there are 93 enemies that are Humanoid in the game.

Allies are expendable, that's why I don't use good ol' Dr. Milan Christopher. Get rid of them as soon as you can to soak damage/horror. In the case of Mr. "Rook", wait three turns till he tells you all his secrets. Don't worry for him, he's just an asshole that wants to get into your pants.

Anyways, this is by far not enough, in multiplayer you can rely on other players' muscle. For solo, you will struggle especially until you can get Disc of Itzamna and Strange Solution advanced. Still, this is by far the weak point of hot bookworm chicks, no matter what.

Upgrades

• Higher Education is of course the first thing to go. Even if you play with the taboo list, it's a great card to make and a sure thing forever, especially with Mandy's drawing surge. Then, we go to the annoying enemies that scare little girls:
• Tooth of Eztli -> Disc of Itzamna to send them right back where they came.
• Strange Solution advanced for evade or fight tests. It's also a theme card as I miss a scientist role in Arkham LCG, and the redhead is a researcher after all. Strange solutions also don't require hands so it's a replacement of what would be Shrivelling or Mists of R'lyeh for Daisy Walker. With Shrewd Analysis we are talking of only 4XP to get both copies upgraded, although maybe you don't get the good ones (50% chances of getting the fight or evade versions for the 1st copy, 57% for the second). If you get 0 or 1 copies for fighting or evading, you can, for just 1XP, try better luck (67% and 80%). It's still better that spending 8XP.
• Studious is a good option to abuse of mulligan and a full hand. Death • XIII is another good option especially if you take (even 2!) copies Studious
• Of course Deduction, but I only recommend it in multiplayer. Solo games tend to have only 1/2 clues per location.
• I don't feel it themed, but Ornate Bow with Dr. Elli Horowitz can be a good option since you have 3 . I am not sure, but with Mandy Thompson I think you can have two relics hosted in Dr. Elli Horowitz, which is a great exploit.