Maria Leticia Alcaraz posted on Facebook about her sister, Lucero Alcaraz, who was killed Thursday

By Sheila Cosgrove Baylis
Updated October 02, 2015 03:00 PM
Credit: Courtesy Maria Leticia Alcaraz/Facebook

Lucero Alcaraz was one of the nine victims of the shooting at Umpqua Community College in Roseburg, Oregon, on Thursday, PEOPLE confirms.

Her sister, Maria Leticia Alcaraz, shared on Facebook Friday that Lucero was a devoted student who hoped to become a pediatric nurse.

“Never in a million years would I have imagined going through something like this. She was my best friend and my sister. Today, I lost her. I can’t begin to describe how I feel. I’m full of anger, pain, sadness, regret that I didn’t get the chance to see her or prevent this from happening,” Maria Leticia wrote.

She later shared some of Lucero’s accomplishments, including getting scholarships to pay for college and earning honors in school.

“Lucero, I miss you I wish you were here, I can’t sleep. I never got the chance to tell you how proud of you I was. You would have been a great pediatric nurse. I was so proud of you for getting you college completely paid through scholarships and you made it into college honors. You were going to do great things love. I ache so much right now. I need you,” she wrote.

Childhood Friends Remember the Girl Next Door

Kaitlyn Ball, who grew up with Lucero, tells PEOPLE, “She was a great girl with a bright future. Some of my most remembered childhood memories were in her house and in her yard considering we would all play with one another everyday.

“She had a big heart. She was such a good girl growing up. And she always came off as very calm to me. Very beautiful. And smart. We went to Rose Elementary lived in the area and lived right next door to one another. All of us girls would walk to school together.”

Adds Kaitlyn’s sister, Jamie: “I spent every single day with her and her family. I can’t stop replaying our childhood in my mind. We would always make mud pies, and pretend that our bikes and scooters were cars, we picked cherries from the cherry tree down the block and would lay in the grass and create pictures out of the clouds.

“We did everything little kids are supposed to do and we had the time of our life’s doing everything together every day,” Jamie says.

Jamie went on to say that she’s heartbroken Lucero’s life was taken from her when she had such a bright future ahead of her. “I will cherish these memories for the rest of my life,” she says. “Lucero was such a beautiful bright young woman who had her whole life ahead of her. She wanted to become a pediatric nurse and she would have had she been given the chance. She had dreams and goals and it kills me to know that those were taken from her.

“Lucero Alcaraz will forever be in the hearts of all those lucky enough to have been touched by her beautiful spirit,” Jamie adds. “She as truly an amazing person so smart and so good. I am still in utter shock and disbelief that this happened to her. I just can’t believe that she is gone.”

On Friday, PEOPLE spoke to a woman at Lucero’s home who would not identify herself, but confirms the 19-year-old was one of gunman Chris Harper Mercer‘s victims. Before hanging up the phone, the sobbing woman asked for privacy during this time of mourning.

Mercer killed nine and wounded seven others, allegedly asking his victims if they were Christians before shooting them. The 26-year-old alleged gunman died after exchanging fire with officers on the school campus, according to multiple reports.