Poppy has a problem and that problem’s name is Sashabella, her big sister. [This sentence is a little awkward] Fashion-mad Sash, a blogger turned designer, has driven Poppy to breaking point with incessant talk of clothes and shoes. Now, Poppy’s out to teach her sister that there’s more to life than looking good. She just needs two large pythons and a little help from Devon, a
famous designer’s daughter; Trina, Poppy’s best friend and a model’s sister; and Max, the cute filmmaker she meets backstage. Together, she and her friends are The SOS Club and they’re going to make sure Sashabella’s debut catwalk show isn’t the sugary pink vision the teenage fashionista had in mind. [Interesting premise for the story, but break up the paragraph a bit - maybe at 'Together ...' Also, what ages are these characters?]
The SOS Club (The Substance Over Style Club) is an 11,694 word story written for [publisher's imprint for older children/adolescents]. [That word count's a bit small for YA] I enclose my entire manuscript [for this was the publisher's instruction].
I wrote this story because I, like Poppy, have an older sister who can be painfully annoying. I remember the battles of childhood and my teenage years vividly. I’m sure readers with siblings will identify with Poppy’s struggles and those of her friends – feeling jealous, angry, petulant, ignored and abandoned are all universal experiences. I’m sure plenty have dreamed of getting revenge in the most spectacular way possible. [Good para]
I also wrote it because I am a fashion journalist who finds people who treat clothes and accessories all too seriously very entertaining. I got the idea for this story after covering Australian Fashion Week for [daily newspaper] taught me that the world of fashion is a funny
place. It was better than being David Attenborough studying an exotic species. The fashionistas in their natural habitat were at once terrifying and hilarious, especially to me, the only female in flat shoes, glasses and not a particle of make-up. [Trim this para a bit]
I have produced short fiction with some success – my story [name goes here] was short-listed and highly commended for last year's ACT Writers Centre Marjorie Graber-McInnis Short Story Award.
I have worked as a [daily newspaper] journalist since finishing my Communications (Journalism) degree at the University of Canberra; before that, I freelanced. Besides writing about fashion, I am a columnist, news reporter and features writer.
Thank you for your time and consideration. I’d love to hear from you. [This last sentence is a good one, and the reason is that it's informal yet enthusiastic - as I've said before, this letter could be the first of many in a business relationship that spans years, and it's good to keep things formally conversational.]
Overall: the tone was very good, and the letter is well composed.
What you haven't mentioned: if you've had any experience writing for children before, or what children's/YA books you love. Children's books are a looping community somewhat bonded by who's read what and who can recommend what and whether or not you liked it ... So some reference points would be good here. (NB: If you don't have any - if you haven't been reading for the age group - you need to before sending out this manuscript.) Also, do you envisage this as a series?