Grace Nyambura Kamau of Kenya was sentenced to closed psychiatric care and deportation.
The Attunda District Court ruled she was guilty of murder rather than manslaughter because she had planned the killings a week before pushing 4-year-old Elias and 8-year-old Tevin into the water in a swimming area near Sigtuna last September, the Swedish news agency TT reported.
"Tevin didn't scream but Elias screamed for a long time. It was loud and he shouted 'no, no, no,'" the mother said during interrogations.
The single mother, who had moved to Swden a few years earlier and allegedly was experiencing financial problems, had become emotionally unstable prior to the incident.
She also said she had planned to drown herself.
"We were all supposed to die," she said.
The court ordered her sent to a psychiatric hospital where, held since her arrest, medical examinations confirmed she has serious mental health problems, TT reported.
Swim Week Miami Beach 2014 [PHOTOS]