Taylor's childhood friend Matthew Wiley told PEOPLE that days before she died, Taylor had expressed fear for her safety at home.
"She said, 'There's a gun in the house and it makes me feel uneasy. She felt so unsafe." Wiley said.
He said that three days before she was killed, Taylor texted him and said she and her mom had gotten into a heated argument about her parents' relationship.
Wiley also revealed that Taylor was scared about her mother having access to guns given her mental instability.
Talking about Taylor's tense ties with her mother, Wiley said that she told him that Christy was was growing anxious about her daughters' growing up and moving out.
Taylor, who graduated from Lone Star College cum laude in 2015, was between jobs and preparing to marry her longtime boyfriend, Juan Sebastian Lugo. The two were set to be married Monday, according to a relative.
Emphasising that Christy's "outbursts" affected Taylor, Wiley said that the 22-year-old was worried about her little sister getting caught in the middle of her family's arguments.
"She always wanted to keep an eye on [Madison] and watch over her because she was scared for her of being in the middle of that situation, She'd say 'I don't know what's going on with my mom. I feel like I should do something - maybe tell her to put the guns in a very safe place where she would forget where they are? I was like "your mom wouldn't do that; you're fine,'" And then this happened. It makes me lose my breath just talking about it," Wiley said.
Taylor and Madison Sheats were fatally shot last Friday by their mother, Christy Sheets, who opened fire on them after calling a family meeting.
Authorities say Sheats had a history of mental illness and that they had been called to the house three times for suicide attempts, though they did not specify whether the calls were in reference to Christy.