If it's juicy inside, then it means that it's viable and that the nymphs are still undergoing development. How did you cut it? Please don’t say that you cut it in half… it’s difficult to tell from the picture. If you just cut off a slice from the side, then you won’t have major problems, just place it back in your container, give it heat, and wait.
When I told you online that it may not hatch, I was basing it on the first picture alone (it seemed like it had the indentations an ooth gets after hatching). Now that you sliced it you have more concrete evidence that it will hatch. Oh, and keeping a small amount of nymphs is not a good idea. Most of them die for no reason at all, so having lots of them (especially when their past their first instar) gives you a better chance of raising some into adulthood. Be prepared to have some fruit flies ready for when they hatch.