I'm re-reading Stephen King's On Writing right now - the best book out there on writing, IMHO. It's wonderful because he discusses actually being a writer, not just the craft. Two different animals. One thing he said that has really stuck with me these last few days: he never really liked Carrie White (of Carrie fame.) At least, he didn't at first. He grew to understand her, to appreciate her motives, but she wasn't someone he'd likely count among his friends. He only stuck with her because his wife liked her. ("Honey, I know you don't want to have dinner at the Whites again. But you can do this for me, can't you?")
I'm in this same predicament. My newest character is, well, not one of my best friends at the moment. She seems to simply float through life with no consideration of others, of how her actions have consequences. She's not evil. She's just immature. But I'm sticking with her. Professor King says you don't really know your characters until you finish that first draft. I agree. Once Autumn (of my middle grade novel Autumn Winifred Oliver Does Things Different) was steered through that first draft, it was much easier to see what kind of person she was, and what kind of person she'd become. So I'm sticking with Hope, and keeping my fingers crossed that she becomes the fascinating young lady I so desperately want her to be.
King stuck with Carrie, and she made him millions. You hear that, Hope? Millions! Now, shape up, missy!