If she is sleeping through the night then, (hard as it is) do your best through the day. While guide routines say 4 hourly at 4mo, many babies just can’t do it. I would honestly stay with 3 if she is content and with luck she may do longer naps in the next month or so. I know my eldest struggled with naps longer than 40/45 mins until around 5mo.
Hard as it is when you have a small baby, but all too soon they grow up, so try to enjoy the unsettled times with cuddling and listen to what she’s communicating.