Characters can have leeway. For me, when a character pulls his own way, that’s a sign that I’m going to end up with so much more than I planned to – It first happened for me way back at the beginning when I was still learning how to string a few words together and make them mean something – I let a minor character (a humble shopkeeper) ramble on and he changed the entire plot, the whole book, brought in a war, threw in some seers, created the Chiddran civilization and enabled my lead villain to become something a mite more noble by giving him a princely crown, and thus created the Khekarian series.
That’s quite a feat for one lowly and undisciplined character meant to appear only once and solely because I needed someone to stand behind a counter.
Needless to say, such unexpected creation proved to be a big gain for me, but how did it come about? I let it occur because I had no real plot at the time, so I was easy with it, even when I didn’t know where it was going. I remember thinking that I could always rip it all out if it didn’t lead anywhere useful or if it tangled up in knots.
It’s very easy to be so tied into what you have already decided on that you don’t allow for any leeway at all, but that might cost you. It’s worth exploring if something tugs you in a new direction. You can always rip it out later if you’re not happy with the results.