5'4" and 50 or 51cm.
In my experience, the height vs size information Trek and several other manufacturers advertise is reasonably accurate:
https://www.trekbikes.com/us/en_US/s...ble_bikes_road
There will always be some guy who's 6'1" and thinks it is normal to ride a 52cm, but it is more reasonable to think that the range of normal heights and normal frame sizes correlate more linearly than the tall people riding the smallest frames.