So sorry to hear you are all still struggling
I know above it has been suggested that she may be lower sleep needs, or need less sleep, but looking at that I wonder if in fact she may need an earlier nap, earlier bedtime, or possibly both? Just thinking 14 months is still 'early' to be on one nap (average is 15 months) and many LOs early on can't handle more than 4.5h A time or so before napping. It looks like more like 5.5h is her norm pre-nap, then another 5.5h after? To me, for a 'typical' 14 month old (though we all know there is no such thing) that is too much A time and not enough nap. Just from personal experience with my two, naps in the 1h30-50 range on one nap suggest over tiredness, and so my suggestions would be perhaps to move her nap back to a set(ish) 12pm, and keep her day to about 12 hours for now. In case it helps to compare, my DD was not high sleep needs at all (nap gone entirely by 29 months) but at this age would have been on:
WU 6.30/7, sometimes later
Nap set 11.45 - average probably around the 2h mark but as high as 3h
BT 6.30pm
Do you think it's worth a try? Even as a short-term thing to catch up a bit - regardless of whether she is overall lower sleep needs, a month or more of long NWs and late bedtimes and she almost certainly has some accumulated OT - if you can get on top of that it may really help x