@Nikki yes that would be a one off and she'd do a longer nap that day too, she always wakes happy so it's an odd one!
As long as she’s getting plenty of nap time then I wouldn’t worry about it if it’s mixed with a long nap. Sometimes if I’m in the car or something one of my daughter’s naps can be super short the length of the car ride but I don’t worry about it cause she makes it up the next nap.
My boy has 90% of his naps at home now which wasn’t my intention but does mean they are very routined, 9:30-11 and 2-3:30 more or less everyday. I’ve moved to a clock based routine with him now also
My daughter it’s always a 2 hour first nap and 1 hour second nap. Occasionally she switches and does 1 hour in the morning and 2 in the afternoon but it’s not common. 20-30 minutes is really short does she do that combined with a long nap?