HI Ryans mum,
to answer your question about why some moms stress about short naps so much:
1. It can be so tiring for both mom and baby. Mom barely has time to herself to shower, take a nap, do laundry, etc.
2. For baby, a short nap is not very helpful...antyhing less than 1 hour, and especially less than 45 minutes is really of no use to the baby. As one other popular sleep doctor says, "it is not restorative." Babies do most of their learnign and processing of they day's activities when they sleep. So if their naps are short, they don't have ample time to do the processing and developing they need to.
3. Good day sleep begets good nights sleep for many babies (but not all). Some babies can't sleep well during the night because they didn't get proper rest during the day, so they have a hard time falling asleep and/or staying alseep. For other babies though (like my dd), her poor short naps never affected her night sleep.
So now I may have got you in a panic, but don't fret! Babies as young as yours are still trying to develop their day sleep so short naps are quite common and sometimes not a lot you can do about them. But by the time they are 5-6 months old it is a good idea to try to "fix" them if they are still taking short naps IMHO.