Being a sister isn't always easy ... but what's the very worst thing about your sister? Marty and her sister Melissa couldn't be more different. Marty loves her Converse trainers, playing football, hiding in her secret den and helping her dad with his DIY. But Melissa loves Justin Bieber and all things pink, girly and pretty. The sisters can manage to live together, despite their occasional scraps but then Mum tells them they have to share a room.

Ruby and Garnet are ten-year-old twins. They're identical, and they do everything together, especially since their mother died three years earlier – but they couldn't be more different. Bossy, bouncy, funny Ruby loves to take charge, and is desperate to be a famous actress, while quiet, sensitive, academic Garnet loves nothing more than to curl up with one of her favourite books.

When life with Jayni's violent-tempered father becomes too frightening to cope with, Jayni, her mum and her little brother Kenny are forced to escape in the middle of the night. Slipping out of the house unseen, travelling up to London by train and checking into a hotel – it's almost like playing an elaborate game. They even make up false identities to protect their secret, and Jayni becomes the glamorous-sounding Lola Rose.

Amy, Bella, Chloe, Daisy and Emily are friends at school and have their own Alphabet Club (just look at their initials!). Daisy is the newest member and is desperate to fit in, even though Chloe is distinctly unfriendly to her at times. Throughout Daisy’s first year at the school, the girls plan ever-more elaborate sleepover parties for their birthdays. Daisy is dreading the time when her birthday comes round as she doesn’t know what her friends will make of sleeping over at her home, with her rather special older sister.

"Where do baby apes sleep? In apricots! I'm Elsa, and that's one of my jokes (I tell LOTS of jokes and I'm going to be a big star one day). I do my best to cheer my family up - but no one seems to laugh much any more. Not since we lost our lovely house and had to move into a bed and breakfast hotel."

India lives in a large, luxurious house with a mum she can't stand and a dad she adores, though he hasn't had much time for her recently. She seeks solace in her journal, which she keeps in sincere imitation of her heroine, Anne Frank. Treasure lives on the local council estate with her loving and capable grandmother. She is devoted to her nan but lives in fear of having to go back to live with her mother and violent stepfather. A chance meeting sparks a great friendship between the girls.

Gemma and Alice were born on the same day and have been devoted best friends ever since. Despite Gemma's larger-than-life personality and Alice's quieter, calmer character, the two are inseparable – until Alice has to move house, all the way to Scotland. Gemma is utterly distraught, particularly at the thought that Alice might find a new best friend. Is there anything Gem's brothers, or perhaps her Grand dad, can do to help?

Victorian London, 1851. Queen Victoria is on the throne, and the Great Exhibition is about to open! Lucy Locket lives with her father, the New Mother and the New Baby. They sent away her beloved nurse and replaced her with a horrid governess. Lucy desperately wants someone to be kind to her and to have some fun - there's very little of that in her house. Kitty Fisher is a street performer who earns tin for her supper by tumbling. She has always lived on the street and on her wits, with only the kind Gaffer to help her. But now Gaffer is gone, and Kitty is all alone. 

Beauty Cookson is no beauty. She's a plain, timid girl who constantly feels inferior to the super-confident, snooty girls at school. Worse than the teasing in the playground, though, is the unpredictable, hurtful criticism from her father. Beauty and her meek, sweet mother live in uneasy fear of his fierce rages, sparked whenever they break one of his fussy house rules.

Floss's parents are divorced, and she divides up her week, spending five days with her mum, her new step-dad and her baby half-brother. The other two days Floss spends with her dad, helping him to run his greasy spoon cafe. But their simple arrangement is thrown into disarray when Floss's mum decides to move to Australia. Making the difficult decision to stay at home, Floss moves in permanently with her dad and they muddle along happily together, surviving on chip butties and enjoying visits to the local funfair.

When Rebecca wades into the witch's pond after a row with her best friend Sarah, she meets a very unusual new friend – a huge, warty toad! And Glubbslyme is no ordinary toad. Hundreds of years old, he can talk and – best of all – he can work magic. Maybe, just maybe, he can help Rebecca be best friends with Sarah again?

Katy Carr is a lively, daredevil oldest sister in a big family. She loves messing around outdoors, climbing on the garage roof or up a tree, cycling, skateboarding, swinging.... But her life changes in dramatic and unexpected ways after a serious accident. Inspired by the classic novel What Katy Did, Jacqueline Wilson creates an irresistible 21st-century heroine. Fans of Hetty Feather and Tracy Beaker will fall in love with Katy and her family too.

A werewolf video leaves Micky terrified of dogs. Mum decides the only answer is to get Mickey a pet of his own. To everyone's surprise -including Micky's - she chooses a werepuppy. But Wolfie turns out to be a very special pet - and a real joker!

Dixie is the youngest Diamond girl. She and her sisters – dreamy Martine, glamorous Rochelle and tough Jude – could hardly be more different, but their mum has always tried to teach them the value of sticking together. Now Mum's expecting yet another baby, and she's convinced this one's a boy. She insists they move to a bigger place – but it's rough, dilapidated and filthy, and before they've even unpacked, Mum's gone into labour!

Hi! I'm Charlie (DON'T call me Charlotte – ever!). History is boring, right? Wrong! The Victorians weren't all deadly dull and drippy. Lottie certainly isn't. She's eleven – like me – but she's left school and has a job as a nursery maid. Her life is really hard, just work work work, but I bet she'd know what to do about my mum's awful boyfriend and his wimpy little son. I bet she wouldn't mess it all up like I do ...