I know you specifically asked for fantasy, but you should look into David Weber's Honor Harrington series. The protagonist is a very strong female who has a lot of growth throughout the series. If you are looking for something epic in scope, it definitely has that. At the time I started it, I didn't read a lot of sci-fi or a lot of military fic, and this series really opened my eyes to the possibilities in both genres.
The books are available for free online, so you can give the first one a try without a lot of commitment or even a trip to the library!
I'm very not good at html, but here is the link: http://baencd.thefifthimperium.com/09-AtAllCostsCD/AtAllCostsCD/
Since I've mentioned Honorverse a few weeks ago on the previous page I have actually read the entire Honor Harrington series (which is 12 books, no less!), and have a few things to say.
First and foremost, be warned that David Weber likes his viewpoint characters. Over the course of 12 books there have been literally hundreds of viewpoint characters. Many of those are recurring, but often DW will tell a part of a bigger event from the point of a minor character, only to kill him or her off shortly afterwards.
The other thing to remember is that Honor Harrington books are military science fiction first, and ordinary science fiction second. Weber often goes on to describe a certain piece of technology, naval tactics or politics for tens of pages.
Now, if you're like me and like to read books for their characters, Honor Harrington is perfectly possible to read without getting yourself entangled in the sheer bone-crushing depth of the fictional universe David Weber has created. I've read those books because I wanted to see what happens to Honor and her friends, not how political coups are executed by Her enemies half a galaxy away. Some chapters I have skimmed through very quickly, some I've skipped entirely, but in the end, I still understood most of the plot's details and generally enjoyed reading the series.
Last, but not least, I have to mention that by the end of the 11th book, Honor Harrington just about reaches the end of her character arc. By now she's earned more titles, awards, commendations than you would have thought possible, she's been through hell and back again to tell, she's the most experienced fleet commander out there... well, you get the idea.
In fact, having partially based Honor on Horatio Nelson, David Weber originally intended to have Honor die in the battle at the end of the 11th book, much like Nelson died at the Battle of Trafalgar. Instead he left Honor alive. For all the good it did, because Honor is completely sidelined in the 12th book, she makes barely a handful of appearances in only about 1/5th of the entire book. But the first 11 books I can definitely recommend.