I'm so sorry Rach, but remind me again about the 2 nap scenario --
Let's say you gave her a 10-15 minute siesta at 10, and then didn't give her another nap until around 2:30. Would she not sleep at 2:30? How would that work? Because in that scenario even if she only slept for an hour at 2:30, that takes you to a 3:30 waking and easily to a 7:30 bedtime. Even with only a 10 hour night, that gives you a 5:30 waking, which is better than 4:30!
But I remember 2 didn't work for you before, I just can't remember why. Just wondering if we can tweak the 2 nap scenario a bit. Since she's waking SO early, 1 nap is going to be a big challenge for her.