I just have a feeling she followed the lead from the questioning and tried to answer, but even she did not recall exactly what happened. I find it impossible she burned the baby enough (if at all) to char bones.
Have you tried to start a campfire or a fire in a burn barrel? It takes bits of crumbled paper or small twigs to catch enough to begin to burn the bigger chunks of wood ... and it better be dry or it won't burn without super high heat involved from an extensive fire.
Surely she could not have practiced what to say, and her responses come too quickly for me to not believe she is attempting to give them what they ask or need, but I think she worked on adrenaline and not thought.
JMO