"They" say that babies usually lose the startle reflex at around 3 months - but as with everything else all babies are different.
As for wrapping, my son was about 5 months old when I finally weaned him off the wrap! He'd started getting out of it at about 4 months as he moved around so much, but he wouldn't go to sleep without it. I asked the nurse about it, and she said he obviously still needs it, but she suggested to start leaving one arm out. So I alternated the arm that I left out each time, so he would be used to having each of them out. Then I started leaving both out and just wrapping around his torso. I think it took about a month to stop wrapping all together. don't stress to much about it - your daughter will let you know when she doesn't need the wrap anymore. I've read in some of the posts on this site about 8 month old babies still being wrapped - I don't think it's a problem until it becomes a safety issue. Just take it slowly and I'm sure your daughter will be sleeping unwrapped in no time. It's funny as when my son was a newborn he didn't like being wrapped, but he slept a lot better when he was, he finally got used to it and I had to wean him off it!!!
Hope this helps