Sleeping too much?

Is my baby sleeping too much? She’s 1 month old and she seems to just sleep all the time, she has quite short wake windows at the moment and tends to just feed for a short while (5-10 mins when used to be around 20) and then goes right back to sleep. Other than having a few gas issues she seems normal and paediatrician says she’s fine but is this fine ? She slept for a 4 and half hour stretch the other night!!

She was born at 36 weeks and has surpassed her birthweight by 1.7lbs now