30 min nap in crib but 1 hour+ nap when being held.

my almost 9month old baby girl needs 4 naps per day because she can only nap for 30 minutes in her crib or stroller. However, if i hold her in my arm she would nap for 1hour+++. I am not sure what to do. Sometimes i just hold her so she gets a good nap but it’s a bad habit.