Is This Jail Sentence Appropriate?

From the Chicago Tribune: A Dallas woman who kicked and beat her 2-year-old daughter and superglued her hands to a wall of their apartment was sentenced to 99 years in prison on Friday."On September 7, 2011, you savagely beat your child to the edge of death," State District Judge Larry Mitchell said in sentencing 23-year-old Elizabeth Escalona. "For this you must be punished."
 The mother of five pleaded guilty in July to felony injury to a child for the beating. The toddler was so badly injured she remained hospitalized in a coma for nearly a week.
During a week-long sentencing hearing, Escalona admitted on the witness stand to kicking and beating the girl. The attack was apparently prompted by toilet-training problems, according to The Dallas Morning News.
After beating the child, Escalona glued her hands to the wall of the family's apartment using the strong-bonding adhesive product, police said.  http://www.chicagotribune.com/news/sns-rt-us-usa-crime-texasbre89b18y-20121012,0,2270730.story
I have to wonder about this sentence of 99 years.
No doubt that what his woman did was horrendous and deserves jail time.
But 99 years?
Maybe a sentence of 27 years, and that would get her out of prison at age 50 and well beyond her ability to make anymore babies.
But certainly not probation, as her defense lawyer suggests.
People have gotten a lot less prison time for murder/torture and baby killing.
So, why 99 years?