Am I setting myself up for trouble? re: sleep/naps

That.Just.Happened

I am still BF and our routine is that E nurses down for her naps. She doesn't necessarily fall asleep nursing, but it is part of our routine: we go upstairs, change her diaper, put her in her sleep sack, then she nurses while I'm sitting in the rocker and goes straight from that into the crib.  Sometimes asleep, sometimes not.  Regardless, I put her down and leave the room and she can put herself to sleep.  Sometimes she goes right to sleep, sometimes she will cry for 30 minutes.  I think that mostly has to do with if I have caught her at the exact right time for her nap (i.e. if I am too late for whatever reason, that tends to be when she cries, but she always eventually falls asleep and takes a good 1.5hr nap).

She is 9 months and I plan to stop BF in the next 3 months.  I never thought I would make it this long to begin with, and I have a girl's trip in November that I don't want to have to pump on, so my goal is to be done by her birthday in October.

I am worried that since her routine for naps is to nurse that it is going to totally mess her up to stop that.  I'd like to start addressing that now if possible so that there aren't a bunch of major changes all at once when I wean her.  Should I go ahead and start trying to change her routine?  Or should I just assume that once she is weaned I will give her a bottle in lieu of BF before naps?  Also, I know that at a year, they can have regular milk: is that in place of BF/formula, or in addition?  At that point is their primary nutrition from regular food?

Her nightime routine has always been a bottle of formula so that DH can do it, so I know she is fine with that.  I would ideally like to be able to simply change her diaper and put her in her crib and walk away for naps, rather than having to feed her then as well.  Is it possible to change her routine like that at this point, or have I created a situation where she is going to have to nurse/have a bottle as part of her routine?  I am fine with CIO, but I want to be fair to her and not just totally rock her world if possible.

Any advice would be great!