they look like a science project gone bad. If they go bad you won't miss it. They turn pink or orange and get dented in and hard. Sometimes they get slimey and usually the substrate you have them in really sticks to them.
Although one wouldn't think she could have been gravid for 6 months with fertile eggs it could be possible. I have one female who wasn't with a male for 10 months after her last clutch when she surprised me with a nice size clutch of fertile eggs. I am guessing that either they can retain sperm or the eggs can go dormant and begin to develop at a later time. I don't know they whys or anything but it is possible.
The only time I had a female lay an infertile clutch without ever having been with a male was one I got as a young animal, too small to be bred, who was kept separate from any males, and at a size believed to be a good guage of sexual maturity developed a clutch of eggs. Funny thing is that she seemed to know they weren't fertile either. She never dug or went through any of the normal preparations. Instead, she just dropped them from her perch in the branch. I found one in the water dish, and one scattered under the branch she was resting on. It appeared that she just pushed them out as she went about her normal eating, swimming, and perching routine.
So, could be young female with infertile eggs, usually only happens with very healthy animal, or she retained sperm from previous exposure to a male. Either way I would keep the eggs long enough to find out.
Other than that, I do agree that she is, beyond a doubt, gravid! 
Marcia
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Marcia - FroggieB Dragons
www.froggieb.com/MHDHome.html
