lacey spears of scottsville , kentucky , was spared the maximum 25 years to life .
spears who chronicled her son garnett 's illnesses on a personal blog called ` unfathomable in its cruelty ' the new york judge who sentenced spears on wednesday said she suffers from a mental illness and said the crime was still ` unfathomable in its cruelty .
spears ' lawyer requested the minimum 15 years to life - he called her a hardworking single mother who gave her son unconditional love .