I agree that Ms. Sprang does resemble Jane and I had looked at her a few times previously as well. It was the colour picture of her on NAMUS that always caught my attention. I always turned away because of her contact with law enforcement in Nebraska - in retrospect I should have given that less credence.
I question the overlay technique. Yes, the prominent facial markers line up; however the overlay uses a forensic drawing. These drawings are often not very good, even the ones made with the aid of a computer. The morgue photo of Jane doesn't look much like her drawing - then again, people look a lot different after they die based on what I've seen on this site.
Wait! You're saying there's a morgue photo? Where can I find that? Yes, that's true; that would be a more reliable source.
As far as accuracy, forensic artists are SUPPOSED to use the exact measurements of the individual, including soft tissue when present. Even when they do that sometimes they change the overall look artistically. When they have a fully recognizable face to work with it amazes me that they can make the person somehow look different, though maybe that is just differences in perception. The measurements, however, should always be maintained.
Many forensic artists trace from a photograph, I've read. And I know sometimes they use the original photo and just apply one of the photoshop filters to it to make it look less real...and they'll possibly touch up skin areas cosmetically (again, without changing structure). That's what I would do...apply the right filter and you can make the picture look less disturbing without altering the identifying characteristics.
Honestly, though, it would be extremely unlikely in this case for everything to line up so perfectly if it had been inaccurately drawn; and by inaccurately drawn I mean departing haphazardly from the preciseness of the source. I suppose it's possible, but extremely unlikely. That would be like randomness creating perfect order.
In this case, our victim died from a "non-traumatic" injury. And while an actual photo would be best, I do have confidence in this artist's depiction. Only because it did line up perfectly. The chances of that happening by accident? Very low.
Interestingly, a few people have said they see Jane Doe the most in Shirley's color photo. When it comes to her color photo I don't see the resemblance at all. Not a bit. I do see it very strongly in her little girl photo, though. And in her young adult photo.