One nap a day - but short!

Mexico

My LO recently transitioned to one nap a day around 12:30 but it's only about an hour! She used to nap 3 hours over two naps. She still sleeps 11 hours at night. I feel she is napping too little but refuses a second nap. She is napping both in the stroller and crib - neither helps lengthen the nap. Any one elses do this? And she's definitely crankier now that she sleeps less during the day!