White Texas Star Hibiscus ''Alba'' (Hibiscus Coccineus)
I believe you have a special plant here TexasWildflower! I have been wanting to to try hybridizing my white and red coccineus' and I think you have one here! It has noticebly blush accents and your leave shape is tad different too.
Make cuttings from this one and see if the seeds produce the same color. Lucky you! Its a unique pretty flower.
I added the pic of mine so you can compare the color and see is you agree?