Why Did My Ball Pythons Die?

[olstyn]

She'd never had any trouble aside from me accidentally suffocating her in my sleep.

Without specific information on what your snakes' enclosure setups were, including temperature, humidity, hides/decorations, size of enclosure, etc, it's going to be hard to provide useful feedback. That said, the part of your post I quoted seems like something worth asking questions about. How exactly did you suffocate a snake while you were sleeping, and what circumstances led to it being possible to do so?