Well we tried 1 nap for 1 day and despite an early bedtime she woke at 1:30am really upset, I guess it was OT, felt like a bit of a step backward in terms of how upset she was but was still quick to resettle her - prob 10 mins.
So yesterday I went back to two naps and she actually took the pm one and she called out about 10:30 but resettled herself so another STTN.
I'm still so pleased because previously if you heard her call out at night you knew it was going to escalate.