First of all, thank you for your responses. It is so good to be able to work this out with someone else's input.
So she could make it beyond the 2 hour mark after that last nap, but it depends on how well those first two naps went. If they are fine and she gets 2.5-3 hours worth of napping in for the day, she could stay up longer. But we limit that because we know that she gets OT not based on last nap to bedtime, but the fact that she has had enough waking hours for the whole day and a 7:30 bedtime seems to be the sweet spot for her. She is temperamentally fine with a later bedtime, but will often take an hour of rolling around to settle, which I see as OT or overstimulated. (She is textbook/angel) I have read that with infants, wake time before bed isn't always an issue, but toddlers need a certain wake time before going to bed, so since she's almost a year, I was concerned about what we were going to do.
Kelly, I like your suggestions. I always thought she could go down earlier in the morning, but because she wasn't getting long enough naps when she was younger, I kept pushing the wake time to take a nice 1st nap. It seemed to be very helpful for having a good 2nd nap and avoiding OT, but in this situation, I see the logic. I think I just need to adjust my thinking towards the 2:1 switch even though I hope it really doesn't happen for a while.
I think I will have to move back her first nap more gradually now that we've been pushing it forward. Any other thoughts?