4 month old napping frequently

I don't know if this is a cause for concern but my 4 month old is napping really frequently. She wakes up, eats, plays a little and then gets really tired. Her total wake time is about 1 hour. Sometimes a little more. This is repeated until ger bedtime of 730 pm. Her naps are about 40 minutes. Am I doing something wrong? Or is this ok? Shes eating normal and seems pretty happy otherwise. Or am I just freaking out for no reason? She was only napping a total of 4 times last week.. its midday and shes had 4 naps already.