New theory: she rotted from the inside out. Wanna know how I found out? Keep reading.
I was doing a regular water change about 15 mins ago, and I was vacuuming the gravel (also hoping to find some hiding babies). The 'possibly pregnant' female got sucked up the vacuum tube. Before I could stick my finger on the end of the tube to stop the water flow, she got sucked up to the top of the 'cup' on the bottom, and acted like a cork for the tube. I put my finger on the end, and she floated back down. That's when I noticed something strange. Apparently when she got jolted at the top, her side split open and some white 'fungus' started coming out. Immediately, I could tell by the way she was swimming that she was going to die. I was right, she is dead, now. That's when I thought, could she have rotted from the inside out? She showed no signs of being sick on the outside.
Any new theories?
BTW, her brother was the one with the 'squiggly' shape before he died. The only sibling left is one of the males, and he is sort of 'fat'. Not like where a female is when she is pregnant, but more up towards his head. I thought it could be overfed, but it's still like that, even after I cut down on the food. This male also gets picked on by the others, so he is obviously the lowest in the pecking order in that tank. I think there is something wrong with this breed line. My other mollies are all siblings, and they are bigger and have better colors, and have never had any diseases.