No, it was NOT thought to be premeditated. She pled guilty to manslaughter, not murder--exactly the same as a heat of passion killing most places. Technically, it may not have met the statutory definition of self-defense. Which, as the judge points out, does not mean that the law shouldn't be changed. If they had gone to trial, they might very well have been acquitted, but there was a risk they weren't willing to take. I can't say they were wrong.
I do think she should have been granted clemency. If it were my case, I would have fought for dismissal of the charges.