Helen Lamb was also ordered to pay 1,500 compensation to the 20-month-old boy, who cannot be named, and 2,000 costs at Manchester Crown Court last week. She was found guilty by a jury last month of inflicting serious bodily harm (News, 15 March).
Ms Lamb had denied fracturing the child's arm by dragging him with excessive force on to a bean bag when he woke early during an afternoon nap at Greenbank Nursery in Cheadle Hulme, Greater Manchester. The boy was in her sole care.
Judge Stuart Fish, who passed sentence, said he had taken into consideration Lamb's previous good character and the fact that it happened during a momentary loss of control. He said, 'What you did was frankly shameful and a breach of trust.
'You showed the boy no compassion and I find it very chilling the fact that you were able to distance yourself so easily from a child you were very fond of at a time when he needed comforting.'
In mitigation, David Lane QC told the judge that she would never work or seek work in her chosen career and that she had 'wasted her past and spoiled her future'.
Ms Lamb was sacked from Greenbank Nursery following the incident but tried to take the nursery to a tribunal for unfair dismissal. She was paid 4,000 in an out-of-court settlement where neither party admitted liability.
Greenbank Nursery declined to comment on the sentence.