My daughter was in the same position, a 14" western saddle when she was 8/9 years old. I bought her a roomy 16.5" English saddle and she didn't outgrow it for about 2 years. As long as your daughter isn't chubby, or if she is, she begins to slim down some as she grows in height (which was the case for my girl), then a 16.5" saddle should continue to fit her until she's about 5'4"-5'6" tall (or a size 4/6 in ladies).
My daughter will be 12 next month and is nearly 5'7" now. She rides in my husband's 18" All Purpose saddle, but fits nicely in a 17" as well. Her new saddle on order is a 17.5", which should fit her through adulthood (I'm guessing she'll be about 5'9" when she's done growing, a good 1.5" taller than mom! lol).
A quality All Purpose saddle is a good choice for a young girl learning English. The deeper seat is more secure and will feel less foriegn. When she gets more serious in to showing or jumping more than 2'6", then a Close Contact or Jumping saddle would be best. However, I thoroughly disagree that All Purposes saddles have no purpose. I teach riding lessons and that's all I have for my beginners, kids and adults. I have only had 2 people fall off in the last 2 years, and both were due to rider error during a spook.
Be sure to look for a good brand name. Look for Stubben, Crosby, Collegiate, Courbette, Passier, Kieffer (hey, you never know what you'll find at a flea market!), Avante, Ovation, Bates, Wintec, or Thorowgood. Stay AWAY from no-name saddles, Borreli, Regent, Kincade, Silver Fox, or anything esle with "cardboard" feeling leather. These are Asian made saddles that don't usually fit horses well and won't last (Borelli is argentine made, but not great). Look for a "Made in" stamp that says any European country, Canada, or Argentina. Though be careful with Argentine saddles. Some are great, some are not. You want to look for soft, supple leather that "feels" quality. English saddles are made with thinner leather than western, so the flaps should be "bendy" if it's a really old saddle, and at least pliable for a newer one.
Last edited by luvs2ride1979; 01-22-2011 at 10:04 AM.