Transition for 2 naps to 1

Maybe she doesn't need one nap, maybe she needs two shorter naps? It seems counter intuitive but when mine have had rough nights I put them to bed earlier than normal and it works every time. 'Sleep breeds sleep' has always been true for me. So maybe she's not ready for one nap a day yet but needs to be waking earlier from her second nap/shorter naps

Our nights were never great, but got realllllly awful when we transitioned to 1 nap. Its been about a month now and its a bit better, but to be honest not as good as when we were on 2. Is your bedtime quite early now? I've found pushing bedtime later (around 8pm) better than when we were doing a 7ish bedtime- from what I've read its just to long for most kids to be in bed so produces spilt nights. But could just be thats she is still adjusting to the 1 nap.. but if bedtime has got a lot earlier, maybe try incrementally pushing it later- its rubbish as eats into your evening, but ive realised all the times my boy has slept better is when he has a later night, but of course all babies are different and my boy still wakes up twice on his best nights!

Our babe generally tends to only sleep for 1 nap when shes at nursery and my parents 3 days a week. But at home were continuing with 2, for now.
Shes got into the habit of early morning wakings though and more distruptions during the night, not sure if its a sign to go for 1 nap days or just teething

Wing and up got the best. Do not let them sleep past 4hrs before bed time (at least that was the number for us)