Started as self defense and ended as a crime.
I would not convict. When a person is attacked you do not have the luxury of opting for the minimum force. (Well occasionally a person does.) But when you use the element of surprise, as in using a handful of cayenne pepper, you can not always be sure that the person is blinded for more than a second or two. Also, when you stab and then slash with a kitchen knife, you may or may not finish the job. If your pepper did not work and the knife stab/slash is not proper, you may end up in a very bad way.
The reason she might walk away is because a jury, who is not under any threat whatsoever, may very well decide as you did.
I am curious, how many years would you put her in jail?
If you would only convict, and not put her in jail, you are removing her from ever taking part in scouts, or any activity having to do with children. She would definitely be barred from purchasing a firearm.
PS, this is just a fictitious story, just for the purpose of discussion.