I'd hang onto her at least another year/breeding. Sometimes the odds just aren't there, unfortunately. You could always add another het female if you have the space; they're pretty cheap, even for one close to breeding age/weight. Keep your current girl, raise another het female up for a year while you wait on breeding season to roll around and give the new one a try along with your current girl in that same season. Even a 100% het to a visual only results in a 50% probability per egg of hatching out a visual animal...aren't recessives fuuuuuuuun?! It all comes down to how much time/energy you want to invest in trying to prove her out. You could try her another year or two and pick up a visual female in the meantime to raise up, depending on what your finances are. Good luck!