The Italian news agency ANSA reported Edda Mellas testified Friday her daughter, an exchange student, got along with Kercher as the two women shared an apartment in Perugia, Italy.
Kercher, 22, was found dead in the Perugia home Nov. 2, 2007. Her death led to charges that Knox, 21, and Knox's former Italian boyfriend, Raffaele Sollecito, killed her during sex games.
An Ivory Coast national, Rudy Guede, was convicted on related murder charges and was sentenced to 30 years in prison.
Mellas testified Friday her daughter called her three times the night of Kercher's death.
Mellas said Knox used the first phone call to voice her suspicions someone might be in her Perugia apartment. ANSA said Knox's mother added that during the ensuing two phone calls, her daughter sounded upset.