OK, so how good are you at framing? You could do a couple of things. The easiest is a regular small , little, tiny, gable ended shed porch type roof.
This you will need to build up on the top at least 3 inches of the window top. You have the room and there will be more room for some insulation, and clearance on the windows to open .Then you build some rafter trusses with 2x4 and plywood. Basically you are making some triangles to screw the back end to the wall, and project over the window. This way the rafters are supporting themselves without a beam. You can go 2 feet on center spacing with some 3/4 inch ply for the roof decking.
I would try to match the existing roof pitch(angle) so it is more in style with the house. This style will leave you with some soffit angles at the window. It will look OK, and leaves you with a bit of roof over the side windows so you can leave them open if it is raining.
Then trim it up, there is really limited weight on this roof so it will work.
The other option is to frame the roof with the hips to match the window angles. This gets more involved but is the same methods.
Good luck, and ask as you go.