The 2-1 nap transition can be so tricky! There's a whole thread regarding this in the sticky section, if my answer doesn't help you.
Basically, what most moms find that works is to shorten the AM nap slowly, so that your PM nap remains stable (around the same time) and the longest.
I was really scared to do this technique, because my LO loved taking long AM naps. The idea of shortening it on purpose really scared me! So I put it off, and put it off, and the resultw as tons of NWs (which has the same cause as the EWs you get). Finally, I gave in and shortened the AM nap and those NWs went away! Well, temporarily until we had to adjust again. They didn't disappear entirely until after we had completely transitioned to 1 nap.
So, usually you will shorten that AM nap to 1 hour, and keep shortening as A time increases. Usually, the last step before totally going over to 1 nap is a 20 minute AM nap and a 1.5-2 hour PM nap.
Your new routine would look like this:
6:30 wake
10:15-11:15 nap
2/2:15-3:30 nap (or so)
7/7:30 bed.
Since you've found that 3:30 is the latest she can nap in order to preserve bedtime, then you will want to adjust backwards to figure out how long that AM nap should be. In other words, my LO would hate a 1h15 nap because it isn't quite 2 sleep cycles, so, that would mean I'd have to limit the AM nap to 45 minutes in order to give him enough time for a 1.5 hour nap in the PM.
It will take some tweaking, but you should find an AM/PM mix that works for your LO. Don't get discouraged! Most babies have a difficult time with this transition, and it often takes some experimentation to figure out the optimal AM nap length in order to get a nice PM nap. Again, most moms find that leaving that PM nap longer is the way to keep NWs and EWs at bay. You also need to give this new nap situation a good week before deciding its not working. Their little body clocks need time to figure out that morning naps are going to be limited, and that they can sleep as long as they need in the PM. After a week, my LO started waking himself from both AM and PM naps at the right time.
Transitioning can take anywhere from 1-4 months, so strap in for a bumpy ride! When you start getting EWs again, you'll know its time to extend A time, shorten the AM nap, and possibly even the PM nap in order ot preserve your bedtime. You may even have a short time where you alternate 1 and 2 nap days towards the end, with very early bedtimes (some of us in the 2-1 group were doing 5:30 and 6:30 bedtimes!). This was the toughest thing I went through, regarding sleep with my baby. But I have to say, the 1 nap is totally worth it! Getting there was interesting, however, to say the least!
Good luck! And post on the 2-1 thread if this doesn't help you, or you still are finding it hard to figure out the right AM/PM combo.
