Nova Scotia Supreme Court Justice Kevin Coady sentenced Susan Elizabeth MacDonnell to two years, plus three years on probation.
MacDonnell bowed her head and dabbed her nose with a tissue as the judge read his sentence.
"Her mental health does not relieve her of all responsibility," Coady said Friday. "Ms. MacDonnell is a very sick woman."
MacDonnell pleaded guilty to aggravated assault and failing to provide the necessities of life in November 2011.
The victim, who was 22 months old at the time, had been living with MacDonnell in February 2010, when she was hospitalized at the IWK Health Centre for dehydration and malnutrition.
Staff at the IWK Health Centre then suspected further abuse when the toddler was slow to recover while hospitalized.
The Crown said the girl nearly died because she was deprived of food for some time.
At an earlier bail hearing, MacDonnell admitted to disconnecting the child's feeding tube in the hospital and to diluting a high glucose formula at least six times.
The Crown had asked for a five-year-sentence, while the defence requested two years plus probation. The girl, now four years old, has been adopted by another family.
Other foster children in MacDonnell's household have since been removed by the provincial Department of Community Services.