A 33-year-old St. Paul woman was charged Monday in Ramsey County with second-degree murder in the stabbing death of her 21-year-old boyfriend.

Melissa Marie Fostvedt intentionally caused the death of Thomas Calvin Donald Jenkins on Dec. 5 without premeditation, authorities say, after arguing over not getting enough food at White Castle.

Family members of the victim say she often hit him, yelled at him and spit on him, according to the criminal complaint from the Ramsey County attorney's office.

Fostvedt, however, told authorities on the day Jenkins died that he slipped on water in her kitchen and fell on a knife. Two of her three children, ages 10 and 7, also said Jenkins, whom they called "Fat Head," slipped and fell on a knife. But the woman's 4-year-old son told interviewers "Mommy stabbed Fat Head" and pointed at his armpit.

Police examined Fostvedt's apartment and found no spilled water on the kitchen floor, the complaint said. Investigators noted that Fostvedt had a cut or bruise on her arm — "and she had no idea where it had come from."

Fostvedt denied being in a relationship with Jenkins, saying he had been spending nights in her apartment "here and there." According to the complaint, she told police she believed his name was Thomas or Tom.

Jenkins' family members, however, said they had been dating for months and that Jenkins had been staying with Fostvedt "off and on."

According to the charges, Jenkins' brother told police the two had met while working together at a cleaning company. Fostvedt's criminal history includes arrests for assault, domestic assault, prostitution and disorderly conduct.

Bail has been set at $1 million.