this is going to be taboo but... put her down on her stomach. It keeps the arms from flailing and it's the only thing that worked for my son who was 9 months before we finally kicked the habit - I thought I'd be swaddling him forever. But the stomach did the trick for us. As soon as your daughter can roll over SIDS risk decreases dramatically. I know it's not PC but it's the only thing that worked for us.
Also, I'd encourage you to break it. #1 the longer the habit goes on the harder it will be to break. #2 I have read a couple articles (all online so take it with a grain of salt) that say that swaddling prevents key muscles from developing by tossing and turning at night and may contribute to delayed gross motor skill development. My son didn't start walking until 18 months.
He is now almost 3 and catching up to his peers although he still seems to be falling at the end of the "what's normal" curve. All that being said, if I had to do it all over again I would still swaddle my son. He is an AWESOME sleeper. I think it is because we set the groundwork early. My daughter resisted swaddling and she is still not a good sleeper.
So good luck with breaking the habit. Give the tummy a shot, it worked like a charm for my swaddle-aholic.