Oslo's appeals court sentenced Yasmin Chaudhry and Ammaz Omer Qureshi to 14 and 16 years in prison respectively, after both were found guilty of voluntary homicide.
The prosecution had asked for prison terms of 15 and 17 years but a lower court had sentenced the pair to eight and nine years respectively and found them guilty of involuntary homicide.
The child, Hunaina Chaudhry, was the woman's daughter from another relationship.
She died aged 21 months after her mother plunged her head into a bucket of water in October 2010.
The murder took place in Oslo after the toddler interrupted the couple during an online video chat in the early hours of the morning.
The man, who was in London at the time, told the woman to "discipline" the child and issued instructions which led to Chaudhry plunging the child's head under water until she lost consciousness.
The couple, both of Pakistani origin, told the court they simply wanted to punish the child.
An inquiry also showed the child had been repeatedly abused. In the last six months of her life, she had been forced to swallow a spoonful of chilli powder, gagged with tape, showered in cold water, slapped in the face and forced to sleep on the floor, all attempts to discipline her, the court was told.
The appeals court likened the treatment to torture.
"The difference is that a victim of torture at least knows why he or she is being tortured and how to put an end to it," the court said in its ruling, quoted by NTB news agency.
After the lower court's ruling, both the prosecution and Qureshi had lodged appeals.
According to NTB, Qureshi, who has consistently rejected the charges against him, plans to take his case to the Supreme Court. Chaudhry, who has admitted to involuntary homicide, has not decided whether to appeal.