is now quite elderly, but she is a British author of mostly coming-of-age type novels. Her most famous series is "Flambards", set around WW I, with the main character an orphan girl sent to live with a landed family.

I came to her because of her fantastic horse novels (though I think even the non-horsey would appreciate them) but she has also written books around sailing and around music, and I've enjoyed all the ones I've gotten my hands on. She has been publishing since she was 15 and has written around 50 novels.

http://en.wikipedia.org/...
http://www.kmpeyton.co.uk/

I love the way that she writes, with humor and with darkness and light.
From Fly-By-Night

Mr. McNair was smiling, but she didn't notice. She was beginning to think that Mr. McNair's ponies might cost more than forty pounds. Everything was so new and expensive, from Mr. McNair's trousers to the first shining bolt that he was pulling back on stall 12. There was no rust at Mr. McNair's, no chipped paint, no dirty straw blowing in the breeze. Only perfection. Ruth remembered Peter holding Toadhill Flax on a quivering rein while he dropped the string. Perfection. "This isn't my sort of place," Ruth thought, and in her imagination she saw a stable yard, slightly untidy, with dipping tiled roofs and pigeons, and stables converted from an old carriage house, with cobbles, and cats, and a faithful head looking over the half-door ... the sort in books. She swallowed desperately.

and its sequel, The Team:

"Ruth!"

Ruth froze. She hadn't expected it to be any different; only it was hard to take. Her mother wasn't one of those noble, understanding, sympathetic mothers that one came across in books: she thought horses a great waste of money anyway, even Fly-sized ones, and the time Ruth spent on them wasted, when she could have been doing something "useful" (unstipulated). Ruth sat down and tried not to listen, but it was very pointed and bitter, and quite a lot of it was true. She started to cry, overwhelmed with weariness and emotion, and at the height of it, her sobs increasing and her mother's invective scaling fresh pinnacles of invention (or was it truth?), the door opened again, and Ted came in.

"Evening all."

His mother rounded on him instantly. "You're to blame, of course! We all know Ruth has absolutely no sense of responsibility at all but you--you're old enough to know better! You--"

"Look, it was my money, not yours." Ted's voice was very firm. "You're losing nothing. We all know she's a lunatic, but sometimes she has to be humored. She'll sell Fly, and everything will be the same as before."

Peyton does a great job of giving her stories the right combination of realism and optimism and building characters with heart who so desperately want to be better at what they do and who they are, even if they aren't starting out with all the talent or resources or family that would help.