Yes, she's probably insane. In any case, you need the details of the case before deciding on a penalty.
Here's some details. This baby had one arm cut off. Then, this baby had another arm cut off. How quickly? How slowly? Was the baby conscious to feel the cutting of the second arm, or had she bled to death by then?
Was Mom doing this in self defense? NO!
Maximum penalty should be served.
The details of the case are she cut off her baby's arms. No decision necessary on the penalty. Fry her.
No details necessary....you take a life, you surrender your own. Just one bullet, that's all the gal needs.