Claire Barker 
Picklewitch & Jack and the Cuckoo Cousin [EPUB ebook] 

NOBODYtells ME what to do BECUZ. I DUZ what I LIKESand I LIKES what I DUZOH YES!Jack's new best friend Picklewitch is still causing marvellous mischief at St Immaculate's School for the Gifted. When she receives a letter from her cousin Archie Cuckoo, telling her he's coming to stay, Jack worries that she'll lose interest in him. But this new cousin turns out to be unexpectedly nice, and it's Picklewitch whose nose is put out of joint when Archie and Jack get along really well. But Archie is not all he seems, and soon both Picklewitch and Jack realise there are sinister plans afoot!