So do you think I should push in a catnap as well & see if it works with her? What time would be ideal?
I just assume that you dropped it recently because of her age. So I would still try and offer if it's only a few days since dropping it so she has a chance to catch up. If it's while since you dropped the CN then I would work ASAP on increasing her A time.
I guess if other naps are going well but the last catnap is still being refused I will be cutting it out by increasing her A time?
Exactly, and perhaps you are in that stage already.
I'm just so confused when to know if a short nap means OT or UT
There are two ways of figuring this out. One is the length of the nap: 30-35min naps are usually OT and 45min-1:20h naps are usually UT. This is a very general rule, yk? Many babies will do UT 30min naps... So the secind way of figuring it out is the way they wake up. If a baby is happy and chatty after a short nap then most likely he is UT, if cranky, crying and seems like he didn't want to wake up then it's most likely OT.
I think in your case it WAS an OT nap because A time was 10min longer than usual butthis is normal and to be expected when increasing A time. IIWY I would stick to the 2:40h A time for 3 more days and increase it again.
Your plan of a routine seems good to me, but you can't just jump from 2.5h A time to 3h, she will get extremely OT.