5 month old naps like 20mins

So my 5 month old sleeps in a dock a tot and she falls asleep ON HER OWN but literally wakes up after 20mins so she has like 5 20min naps a day and it’s driving me insane.

Is this normal for her age? I make the room exactly like it is when she sleeps at night. At night she sleeps a whole 12 hours (with waking to eat once) but goes right back to sleep.

Any ideas on how to get her to sleep atleast an hour? I try to get her back to sleep but it doesn’t work.