Authorities were called out to the 17800 block of Adlong Johnson at about 3:48 p.m. to respond to the citizen call. HCSO said a woman requested a deputy at the location.
When deputies arrived, they spoke to the woman, whom they believed had called, and she told them she had killed her granddaughter and her boyfriend.
Deputies went inside the home, where they found another woman dead with apparent gunshot wounds. A man was not found at the scene, according to HCSO.
At the scene, deputies said a couple owns the home but is out of town. They said the suspect, identified as Courtney Smith, lives at the home, as well as the victim, identified as 21-year-old Maysie Murphy.
Her family shares statements with Eyewitness News as they remember who she was inside and out.
"Maysie was such a blessing to be around. She was such a great sister to her siblings and always there when someone needed her. She would light up any room she walked into," wrote her mother, Rachael Novak.
"Maysie loved and was loved by anybody who's ever come in contact with her. The world is definitely a darker place without her. Taken from us so early. The hole and hurt are felt by so many; may our daughter rest easy," wrote her father, Patrick Murphy.
Authorities said that prior to this call, they had received a call from the suspect saying she was seeing demons and things of that nature, but there wasn't enough information for deputies to proceed with any emergency detention orders.
Smith has been booked into the Harris County Jail on a murder charge, according to Gonzalez.