Fiona Donnison, 45, must serve at least 32 years before release, the Daily Express reported. The sentence was handed down in Lewes Crown Court immediately after Donnison was convicted of murder.
Paul Donnison, 48, her ex-partner, was bitter after the sentencing.
"I attended court as often as I was able to, but often felt that it was I that was on trial," he said. "In addition I had no voice to speak for (the victims) Harry and Elise."
Investigators said Fiona Donnison smothered the two young children last year at her home in Lightwater in Surrey. She then took the bodies, zipped into carrier bags, to Paul Donnison's house, planning to make it look like he had killed the children and then himself.
When Paul Donnison did not return home, Fiona Donnison overdosed on sleeping medication and went to a police station.
The couple, married to other people when they first met, had another daughter, Mia, born in 2003, who died of what was determined to be sudden infant death syndrome at 8 months.