I agree, I was a bit surprised when I saw the black turtleneck picture, but it does essentially match one aspect I have mentioned before; with her upper arms more or less pinned behind her sideboob (actually they are not fully pinned behind), her boobs extend out past her wrists, her hands, and almost half way down her extended fingers. For someone 5'6", I have to imagine that must be at least 13.5" and this tends to support her inability to touch her own nipples when reaching underneath.
The thing about estimating volume by sphere is it fails to take into account the area of attachment. A 8.5" bowling ball resting on your chest has maybe a 1" diameter point of contact. Beshine's breasts are not spherical because they have what I estimate to be a 7.5" area of contact, which is a sphere with a large flat side.
At one time, I was using a dome calculator, however, as her boobs kept expanding, it became obvious that it was not accurate, that a better shape would be a partially filled sphere, because that accounts for the flat area of attachment as well as the increasing diameter (something you can see in today's picture). Assuming a 7.5" area, that gives us a 14" diameter at essentially the crest, which does match up with the 28" total width, which does match up with her boobs resting on both arms of a chair, and supports her saying that she has to turn sideways through doorways.
Most implant girls have a far smaller diameter area of attachment. Even standing up OF pic from a few days ago, you see it extends from the axillary to what I have to imagine as the bottom of her rib cage (once again supporting a contention of having at least a 7.5" attachment area). This has led me to believe that the base of her implants is likely very close to that diameter because she has essentially no underboob crease today; her implants must be close to their designed volume now.
I'll let you play around with the numbers and using a partial sphere calculator, but I'm pretty sure you will find it points to likely being more than 23K.
The bowling picture set is from August 2010, probably in the 8k timeframe. I bet she cannot bowl today.