My lo is also a poor napper and did 1 hr 15 min naps for a long time when she switched to one nap around 15 mths. Her night sleep was always long 12-12.5 hrs. She also had a very short A time in the morning, usually 4-4.5 hrs and then a longer A time after nap which she seemed to handle better. Then around 21 mths, she started doing better, many days at 1.5 hrs and even some 2 hr naps, maybe 1-2 times per week. Her A time at 21 mths was 5 hrs and now at 27 mths is 5.5 hrs. She has never been great at napping though and still occasionally has short naps. I think some kids are just destined to be bad nappers but the good thing is that they are usually great at night!
I guess I just never worried so much about the longer A time after the nap but we never had any NW or EW from it. So at your lo's age, our schedule was wake at 7:30, nap at 11:30-12:45, bed at 7. Also, I started leaving her in there for as long as I could and now she stays in there for at least 30 min after she wakes and sometimes tells me to "go away" and says "stay in crib", lol!
I wonder where they all get that 1 hr 15 min length??
Aileen