She later died in a coma at King’s College Hospital in London.
The jury heard Everson, who lived in Haselbury Road, in Edmonton, London, had begun a relationship with Burdett, of Nightingale Road, Rickmansworth, Hertfordshire, when she was pregnant.
He was alone with the baby when the fatal injuries were inflicted, but told emergency services she choked and stopped breathing while he was feeding her.
Prosecutors said the brain injury suggested a “strong possibility of a non-accidental injury having taken place” and it was likely Everson injured her by “shaking or throwing her against a surface”.
The baby was later found to have suffered 12 fractured ribs and two leg fractures before the fatal assault took place.
The jury also heard Burdett “failed to take reasonable steps to protect Millie” and “covered up for [Everson]”.
Passing sentence, Mrs Justice Cheema-Grubb said it was a “sustained assault on a small baby” and, referring to the existing injuries, said Everson had “caused her acute and lasting pain for half of her short life”.
“One of the things that upset you, Everson, was that Millie-Rose was beginning to resemble her biological father, and that riled you,” she said.
Everson and Burdett were also given four and two-month jail sentences, respectively, for cruelty to a person under 16, involving another child who cannot be named.