Sorry for the late reply trimble...
What is your eventual goal? Is it like a 1 x 11.30 am nap? If it is, that way not only would you get hopefully a longer sleep, but then it moves out towards the middle of the day and then would also have a nice side affect of not interfering with your pre-school drop-off too. The nap time a lot of us are on around here is 11.30am (or thereabouts).
My LO has a cuski toy as her lovey. She absolutely loves it! But she has had it almost from birth. I think if your daughter takes to one then thats great as it is a good, portable sleep association that can go to daycare, to grandmother's house etc. BUT if its not your daughter's bag then it won't achieve anything I guess?!
The sleeping bag thing.... my LO is in them and the longer they are the better. I usually go next size up not only to make it a big cheaper so we can get more wear out of them, but also so that there is plenty of room and she doesn't get so tangled.
Now your daughter is crawling and moving around in her cot, don't worry this doesn't last long IMO - maybe a couple of weeks. If she isn't going to sleep I would just go in there, place her back in her sleeping position, tuck her in tightly if you use blankets with your sleeping bag (and if not, maybe just a larger sheet sideways to tuck her in tight), lots of shhshhhhsssshhh and night night, sleep time etc etc.
Honestly though if your LO has been sick I would just focus on trying to get her back to the old normal and then go from there. Don't stress too much about what has happened in the previous weeks, hey what happens happens, that is life eh!
Hope the above helps! All the best