Khanya also appealed to God to heal her family, her sister's friends and women in general.
"God. Take me deeper than my feet could ever wander, where my faith will be made stronger. All the other times I said I was hurt or I was crying, I was probably being impossible. Nothing compares to what I'm feeling right now.
"All air has left my lungs and my heart is right there below my knees. But even so, it is well with my soul. It's so much more harder to remain safe.
"I will never question God but I ask that He heals our hearts as your family, your friends, as women, as a country and we remain stronger in faith. Uyinene, you're still my baby sister and always will be. I love you so much Nene wam', Bhelekazi, Mafu, Ndabezitha, Langa lokulungu. Fly away my butterfly."
Mrwetyana, 19, disappeared more than a week ago.
The man accused of killing her made his first appearance at the Wynberg magistrate's court on Monday. The state alleged he had bludgeoned her with a scale after luring her into the post office. The accused's house was burnt downby Khayelitsha residents last night.
'Killer rapist' soft-spoken churchgoer
The man charged with the murder and rape of UCT student Uyinene Mrwetyana was a loner, but his neighbour never thought he would commit such a heinous crime.
The 42-year-old man, who cannot be named because he has not yet pleaded to a sexual offence charge, was described by his neighbour as a soft-spoken church-loving man with a small body frame who often kept to himself.
The man, who is said to have confessed to the killing and rape this week, lived alone after his wife and daughter left his one-bedroom Khayelitsha home in Cape Town.
Mawethu Mgojo said the man moved into the area with his wife and newborn daughter in 2017.
He said he had lived alone for about a year and was very humble and generous. "I've never seen him with another woman since his wife left him around this time last year.
"When I didn't have a car, this guy would offer me his own car to fetch my mother."
Mgojo yesterday expressed his dismay and disappointment after it had emerged that his neighbour had confessed to the crimes. "Not in a million years would I have suspected him in any way.
"He is one guy who kept to himself. Soft-spoken. Even today, I am in disbelief. I trusted him with my life and my sisters," Mgojo told Sowetan.
He said although his sisters knew how fond he was of the man, they however thought he was "creepy".
"Of which I would just shrug that [his sisters' views] off," he said.
Meanwhile, Mrwetyana's older sister Khanya also took to Facebook to express her pain and asked for divine intervention.
"What haunts me the most isn't the fact that you're gone and taken away from us so soon, it's the thought of the fear and pain you experienced all alone. I'm so sorry Bhelekazi.
"I'm so sorry you had to be alive at a time where being a woman is all it takes to set a man off.
"Now we hold on to the memories we shared together and the thought of what could've become of you had that man not violated you. Hurt. - That's what I am. That's what we all are. Such a beautiful soul with an entire future and opportunities awaiting her," wrote Khanya.
Khanya also appealed to God to heal her family, her sister's friends and women in general.
"God. Take me deeper than my feet could ever wander, where my faith will be made stronger. All the other times I said I was hurt or I was crying, I was probably being impossible. Nothing compares to what I'm feeling right now.
"All air has left my lungs and my heart is right there below my knees. But even so, it is well with my soul. It's so much more harder to remain safe.
"I will never question God but I ask that He heals our hearts as your family, your friends, as women, as a country and we remain stronger in faith. Uyinene, you're still my baby sister and always will be. I love you so much Nene wam', Bhelekazi, Mafu, Ndabezitha, Langa lokulungu. Fly away my butterfly."
Mrwetyana, 19, disappeared more than a week ago.
The man accused of killing her made his first appearance at the Wynberg magistrate's court on Monday. The state alleged he had bludgeoned her with a scale after luring her into the post office. The accused's house was burnt downby Khayelitsha residents last night.