Ochoa-Lopez was 19 when she was killed in 2019, and her unborn baby was cut from her womb in a home in Chicago's Scottsdale neighborhood.
A mother and daughter who allegedly wanted the child for themselves were charged in the case.
Desiree Figueroa pleaded guilty to murder in a Cook County courtroom Monday morning.
Her mother, Clarissa Figueroa, is expected at a hearing Tuesday.
Clarissa Figueroa's boyfriend was released on parole last year after pleading guilty to helping conceal the murder.
Ochoa-Lopez's baby survived for only a few months.
During a four-year anniversary vigil in April, Ochoa-Lopez's family said life will never be the same.
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