It willd depned on the size of your headers and perhaps other obstructions. 48” would work in many but not all and you may be able to takler than than that.

Also depends on the room the windows will be in as the rules are different for bedrooms due to egress requirements.

What’s up with the 3’ restriction? Is this a kitchen? Bathroom?

Its a small poolhouse bathroom. The window is right next to the toilet.

The standard for the top of windows is the rough framing is at 82.5" - 84". It is based on standard 80" door height, not ceiling height. You are free to deviate from the standard based on whatever height you want: ceiling; window size; flagpole . . .