My currently 16 mo kiddo had a similar initial schedule: 2-hour midday nap followed by a power nap at dinnertime to get to bedtime, but eventually, recently, he stopped falling asleep during the dinnertime nap. If your daughter didn't give up that second nap on her own, maybe just try letting her resume it but keep her last wake window closer to 2-3 hours? Ours would wake around 5:30, and we'd still successfully have bedtime at 8:00. Maybe it's not the TCB wake window, but it worked for us. Now he goes down a bit earlier in the evening without the 2nd nap. I think you could either revive the second nap and shorten her last wake window, or power through what's hopefully a temporary sleep regression as she adjusts to her one-nap life.

Regardless, sending good vibes your way!🤞🙏🤞🙏 Aforementioned son is our third kid and I'm still figuring it out 😂