Are the pinwheels around the frog a red and white print? If so I would try a border of red with tiny white flowers, sort of opposite of the pinwheel print. That would liven the whole thing up. It would not have to be really wide. I'm thinking a 2 or 3 inch red with white border and then a white with red border whatever width you wanted.
Really nice quilt, but the navy seems to suck the life out of it.