There is a genre exactly for your daughter -- Young Adult! It's really popular right now, with a lot of AMAZING books written by AMAZING authors. I have a couple friends who are YA authors and I'm working on a book myself.

There are many that I haven't read but have heard good reviews on, but I'm only listing those I've personally read.
I am an "anything and everything" kind of reader (and always have been!!), so these might vary depending on your daughter's maturity/ability. If you let me know that, I can be a bit more specific. If you're super-conservative some people may say a few on this list are inappropriate (sex/religion/etc) but at 14 I wouldn't think they are inappropriate at all. Just tossing in a fair disclaimer that if you worry about that kind of thing, you may want to skim first.
But lately I have read (in the YA genre) and loved:
Harry Potter (completely classic)
Cirque Du Freak series (7 or 8 books total, completed) (recommended to me by a librarian for my brother, but I liked them too)
Percy Jackson series
The Hunger Games & Catching Fire (final book coming this fall) by Suzanne Collins
Uglies series by Scott Westerfeld
Anything by John Green -- Looking for Alaska, Paper Towns, etc. (John Green books are VERY good. lots of life lessons.)
Knightley Academy by Violet Habberdasher (to be a series)
Beautiful Creatures (sequel coming this fall) by Kami Garci and Maggie Stohl
Shiver (and Ballad and Lament) (sequel to Shiver coming this fall) by Maggie Steiveter
The Lonely Hearts Club by Elizabeth Eulberg
If she hasn't read the Twilight Saga, she might enjoy those (4 books plus a novella, completed, I wouldn't recommend reading the 4th book though)
Brightly Woven by Alexandra Bracken (loved this one!! very different from most modern YA)
Mortal Instruments Series by Cassandra Clare (3 books, another one coming in 2011 and a prequel coming this fall) (I could re-read these books all day... I carried one with me almost the whole fall semester. they are on the longer side but SO GOOD.)
Wicked Lovely series (4 books so far) by Melissa Marr (I Wasn't a huge fan of these but know a lot of people who love them)
The Luxe Series (4 books, completed) by Anna Godbersen
His Dark Materials by Phillip Pullman (3 books, completed, AMAZING works of literature and one of my all-time favorites)
Bran Hambric and the Farfield Curse by Kaleb Nation (to be a series, next book coming in the fall)
Currently reading The Demon's Lexicon and Eat, Pray, Love... I think the 2nd one is a little mature for 14, Demon's Lex is good so far though.
Keep in mind Book Expo America (BEA), the book industry trade show, was just held the last week in May, so a lot of sequels will be out in the fall. But it's a perfect time for her to pick up a couple books and read them before the much-anticipated sequels come out!!
There are a lot of other popular vampire series now as well, but I can't say I've read any of them besides Twilight and CdF
Hopefully there will be something she likes!

I adore reading... I just got a nook because I have filled my parents attic with books!!