Actually we have been trying to put her down for a third nap day after day but she won't go down. I typically try to put her down every two hours (since the naps are always short).
I think part of the reason is that when we put her down, she stands up in her crib and even though she's tired, she gets really excited and ends up not being able to sleep. She doesn't cry or anything, she just coos and babbles and plays.
And on the days she sleeps only 30-60 minutes she doesn't have meltdowns or anything, she just gets kind of tired, her eyes look a little baggy, she become more sensitive to loud noises, etc. but overall she's pleasant.
I'm guessing I have one of those 5% of babies who need very little sleep during the day?