Hooray for bf-ing and cosleeping!
Every family is different. I can tell you what worked for my family.
Also, I don't know that you're wanting a "schedule" so much as a "routine". An 8mos old baby needs more sleep than 10p-7a will let her get. I would guess something closer to an 8p-7a night with a 2hr nap after lunch. At this point, my 2y and 5y both sleep from 8/8:30 - 7a every night. Neither of them nap any more, but they both sleep through. At 8mos, they were both still sleeping quite a bit.
I agree with those who stressed consistency. I don't go in and wake my kids...never have. What I have done is opened the door a bit more, turned a hallway light on, and made a little more noise than necessary. I would recommend making sure your house is very light during the day. When you want her (body) to start winding down for the night, close shades, less light, etc. I also have black-out fabric in the window. Having a regular bed time routine can do wonders for getting her to sleep (closer) to when you want her to sleep.
As you're bf-ing, I will say that as long as you're changing/messing with her sleep -- do not change anything in your nursing relationship. Let her deal with one change at a time. Most everyone prefers transition to multiple sudden changes, babies are no exception.
I don't know what kind of co-sleeping you are doing...in the bed with you? Side-carred? A separate bed altogether, but in the same room? These are all considered "co-sleeping".
For my babies, sleeping habits seem to change around the time they start crawling (and teething!). That this happened for you at Christmas time may have caused some of the extra...fun :-)
What worked best for us was to side car a twin mattress. I could nurse my baby to sleep and then get back in my bed afterward... I had a bed rail on the outside of the mattress so baby couldn't roll off (easily).
Sometime around 1yr of age I intro'd a water sippy and a soft "lovey" into the bed. Just some thoughts.
HTH and again every family is different. In the end, YOU get to decide what is best for your family.
K., mama to
Catherine, 5y
Samuel, 2y
EDD, 9/09