However, the Crown claimed that Tooman had assaulted her daughter while her older children were in another area in the house.
After noticing the baby was struggling to breathe, she sought the help of her brother who called an ambulance.
At hospital doctors found that the baby's skull had been fractured, she had bleeding on her brain, severe brain damage and injuries to her neck ligaments.
Her right femur was shattered and left tibia had also been broken.
Leading paediatrician Dr Patrick Kelly, who helped to care for the baby in hospital, revealed the baby's brain damage would cause severe disability, but the true extent would not be known until she grows.
He concluded that Tooman's version of events could not explain her daughter's injuries and claimed they were 'non-accidental'.
Justice Anne Hinton agreed with the Crown medical experts and Tooman was found guilty of grievous bodily harm with intent to injure.
She is due to be sentenced in June.
