Sharon Hinojosa wanted to cement her relationship so she started the blaze at her Huron Township, MI, trailer which killed her children Anthony, four and Alayna, three.
The man, who she pulled from the flames and his child escaped the inferno.
Sentencing her to life behind bars,, Wayne County Circuit Judge Daniel Hathaway said her acts "constituted a complete betrayal of what being a mother stands for."
But the 31-year-old claimed she loved her kids and apologized for her actions.
"You think you're mourning? I'm mourning, too," she said.
Her family couldn't sympathize and Alayna's grandmother, Denise Jones, told WXZY it was cowardly for Hinojosa to "disregard these children like a bag of garbage."
She added that she hopes that while in prison, Hinojosa hears her children asking: "What did we do to you? to deserve an awful death."
Attorney Ira Harris read a statement on behalf of Anthony's grandparents which read: "Even wild animals would go to great lengths to protect their young."