I don't think you totally missed your chance yet. Are you sure she's not glowing anymore, is she maybe in shed? Something I've noticed is that they glow the most right before they ovulate. I've been really trying to pay attention this year to see if it holds true for all my females and so far so good. Is she staying on the cool side, warm side, moving around? I had a female eat all the way up to the day she laid last year, so don't give up just because she's eating. They can reabsorb their eggs, I'm not sure what they look like when that happens, but hopefully that's not the case.