Taylor Sheats was due to be married this week. Instead, her mother killed her.

Taylor Sheats should be happily married by now. But her own mother robbed her of that chance, mercilessly gunning down the 22-year-old and her sister during a family argument on Friday.

The women’s grandmother, Ann Sheats Wooten, revealed the impending nuptials on Facebook, writing that Taylor had planned to wed her partner Juan Sebastian Lugo in a small ceremony today, Texas time.

“They were to be married Monday,” she wrote, “and later again after graduation from college with a big wedding.”

Taylor Sheats with her partner and his family. Image: Facebook.

Sheats Wooten's comment was in response to a post by a relative of Lugo's, which read: "Yall were apart of our family, and that will never change. The greatest in laws any one could ever have, and the sweetest, most wholesome and caring girls in my life. I look up to yall so much. Y'all were a light in the midst of this crazy world. We will all love you two untill the end of time. [sic]"

The couple's social media accounts are full of loving pictures together, including several featuring a promise ring Jaun gave her in 2013.

The heartbreaking revelation comes as police discover more details about the events leading up to the women's deaths, reports ABC13.

Police found Taylor and her 17-year-old sister, Madison, lying in the street outside their family home in Katy, Texas, at around 5pm Friday afternoon following a 911 call of "shots fired".

Their mother, Christy, was standing nearby clutching a .38-calibre handgun. When she refused to drop the weapon, a Fulshear police officer fired a single shot, killing her instantly.

Investigators now believe that the violence began with a family meeting that had been called by Christy that afternoon. It was then, they claim, that the 42-year-old fired the first shots.

The women and their father, Jason Sheats, fled in to the normally quiet cul-de-sac, where Madison collapsed and died.

Jason, who was uninjured, managed to seek shelter in a neighbour's home, as Christy returned inside to reload her weapon before emerging again to shoot Taylor where she lay.

After police shot and killed Christy, Taylor was airlifted to a nearby hospital where she was later pronounced dead.

Taylor Sheats and her mother, Christy. Image: Facebook.

Police have refused to comment on a motive for the killings, but confirmed that officers had been called to the Sheats home on 14 previous occasions.

A Fort Bend County Sheriff's Office spokesperson previously told People that some of those visits stemmed from "altercations" relating to a "mental crisis" Christy Sheats was undergoing at the time.

Investigations are ongoing.