( CNN ) An American teenager who helped her boyfriend stuff her mother 's lifeless body into a suitcase at an upmarket hotel in Bali has been sentenced to 10 years in prison . Heather Mack , 19 , who gave birth to her own daughter just weeks ago , was found guilty with her 21-year-old boyfriend , Tommy Schaefer , of killing Sheila von Wiese-Mack on the Indonesian island last August . Schaefer was sentenced to 18 years in prison for battering von Wiese-Mack to death in room 317 of the St. Regis Bali Resort . Schaefer had claimed he killed his girlfriend 's mother in self-defense after a violent argument erupted over the young couple 's relationship . The beaten body of von Wiese-Mack was found in a large silver suitcase that the couple had loaded in a waiting taxi outside the resort . They told the driver they 'd be back soon , but after a lengthy wait he alerted hotel staff who inspected the bag , noticed blood and called police . The lovers were arrested after being found the following morning at another hotel about 15 kilometers ( nine miles ) away . Inside the bag , von Wiese-Mack 's body had been wrapped in hotel bedding . A forensic examination determined that she had died from a blunt force to the face that fractured her facial bones and caused her to suffocate . Described as a Chicago socialite , von Wiese-Mack was reported to have a troubled relationship with her teenage daughter . Schaefer denied that the murder was premeditated . He told the court that he acted in self-defense when his girlfriend 's mother started strangling him during an argument in the Bali hotel room . `` She squeezed my neck for about 20 to 30 seconds . I could n't breathe . I had blood going to my head and my eyes were so watery , '' Schaefer told the court . He said he reached for a nearby bowl `` before she could . '' `` I could n't see for a moment because my eyes were so watery and I was distraught , I was in a state of mind , I had no idea what was happening . I was almost about to black out . And I grabbed it and I started swinging , '' he told the court . Mack told the court her mother had threatened to kill the couple 's unborn baby , according to local media . The prosecutor alleged that the two planned the murder , because Mack 's mother disapproved of their relationship . After being detained by police , the couple initially claimed they 'd been taken captive at the resort by an armed gang , whose members killed Heather 's mother , and from whom they managed to escape . The two were tried separately , though both trials were heard by the same court , with the same prosecutors . Prosecutors had sought a prison sentence of 18 years for Schaefer and 15 years for Mack . Under Indonesian law , Mack will be allowed to keep her baby with her in prison for two years , after which she can nominate who should take custody . Journalists Fairuz Husaini and Ragil Lestari and CNN 's Kathy Quiano contributed to this report .
Heather Mack jailed for 10 years over mother 's murder in Chicago . Boyfriend Tommy Schaefer sentenced to 18 years in prison for the attack . Mack gave birth to the couple 's daughter last month .