a bit off topic, but when I lived next to Hyde Park, what was more traumatising than the squirrels was a pigeon I saw once the size of I kid you not a chicken (!) and it just stood in the middle of the path and wouldn't move and I was scarred it would attack me so I had to change my path :')London Squirrels are scary (and I am from Australia, so used to threatening small creatures ). They've got too much self-confidence
I don't think Jade has the worst study skills - sure she didn't get into Oxford but I'd say it's because since they only have so many places they take good grades and natural intuition/intelligence. Jade got three A stars (unlike Ruby who pretends to be more hard-working!) and still got into RG unis. She probably can achieve the grades without being crazy intelligent.
Now I think the book isn't relevant since they have changed a lot of curricula and as said, what she does NOW at uni is ridiculous.