I co-slept with all 4 of my kids through to at least their first birthday, so I'm completely supportive of that. It CAN be done safely (especially with a 9 month old, who isn't exactly going to take being rolled over on passively!), and is done in the majority of the world. I'm sure you know this, I'm more responding to the other poster who said it was dangerous.
So anyway...the most waking I ever had at this age was every 3-4 hrs, and I had chalked that up to my working out of the home so my kids wanted milk "fresh from the tap." LOL. I was able to nurse while barely waking up, so this was not a problem for me--we were all well rested. Putting my first daughter in her own room--even though it just meant getting up ONE time at night and getting up a bit early to nurse before showering, made me into a walking zombie in just one week. That was why we started co-sleeping. So if you are getting enough sleep and your DD is getting enough sleep, I wouldn't worry too much about the current sleeping pattern.
If you *aren't* getting enough sleep...then by all means, do something. Make sure your DD really is waking up--that it isn't just you rushing to comfort her as she passes through a light sleep phase. You could try putting a crib with the drop down side removed right next to your bed (tie the legs of the crib to your bedframe so that it can not shift away) so that your DD is a bit further away from you so that you are less sensitive to her little noises.
If she really is waking up, you might try having your hubby offer her a sippy cup of water rather than you nursing--this is how I night weaned my first daughter (she was 14 months at the time). Eventually she decided it just wasn't worth it to wake up. We do give our kids a sippy cup of water to take to bed as long as they want one--usually until they are about 3. After that, they can go to the bathroom and get a drink if they want in the middle of the night.
Elizabeth Pantley's book "The No Cry Sleep Solution" has a lot of good suggesions on how to reduce night waking. I'd encourage you to check this book out.
Hugs & good luck!