hiya melissa. Have you done a thread about this
as I don't think this is 18month regression stuff anymore. TBH hun, I think she is UT. She's only been doing a 5hr A time before her nap & this is really short for her age now. I think this is why you are a) getting the resistance & she's not falling asleep (b/c she simply isn't tired enough to) or b) if she does nap, then it is likely this is why you get the bedtime resistance, because with a short AM A time followed by a long nap, she will still be UT at BT.
Oliver is now doing 6hrs A time in the AM before his nap, and napping for 1h 45mins (capped), with a 5hr A time to bed. He is starting to get UT with this & we are also getting some earlier WU's so I'm on the verge of capping at 1.5hrs. I've had to accept that at this age I'm simply not going to get a 12hr night plus a 2-2.5hr nap anymore & I think its likely this is what's happening with A too - her sleep needs are reducing as she nears her 2nd birthday.
I wonder if you try extending that AM A time a bit whether she would take the nap more readily yk? Perhaps shoot for more like 5.5 or 6hrs A. Of course, if you do this you will be unlikely to be able to keep the long 2-2.5hr nap as she probably won't be tired enough for bed. So you may need to start capping the nap. Or, if you are happy for her to keep going to bed at 8pm & wake at 7/7.15am (which is still a great night & exactly what Oliver is doing right now
) then I would probably wake her in the AM if she doesn't wake herself, offer the nap at 1/1.15 & get her up by 3pm at the latest, keep bedtime at 8pm so she isn't UT at bedtime. You might find she will manage this just fine & keep on napping.
Did the no-nap days happen on days she woke at 8am, or did they happen on days she woke at 7.15am?
I think all you can do is keep offering the nap & if she still doesn't go down then you offer an early bedtime & accept this may be the very start of her 1-0 i.e. dropping the nap. This can take a really long time so try not to worry! Also I do seem to remember reading lots of threads from folks with LO's approaching age 2 who say they suddenly get nap refusal & worry its the end of the nap but then after a couple of weeks they suddenly start napping again so it may just be a passing phase.