Friends of a 33-year-old mother who was killed, allegedly by an ex-boyfriend in Mabopane, north of Pretoria, are shattered that all the warning signs of an impending tragedy were there.

Metro FM Radio personality Masecheba Ndlovu was the first to tweet: "She broke up with him, she posted that she's being stalked, nobody took her seriously, last night he stabbed her to death."

Sheila Mosidi Kopanye, a clerk at the Temba Magistrate's Court in Hammanskraal, died on Friday evening.

Her social media comments provided chilling evidence of her being followed against her will. But nobody acted.

"If a relationship is not working out bathong, let's call it quits and move right along," she posted on Facebook.

Kopanye's killing sent shockwaves through social media at the weekend.

Users said Kopanye had spoken about being stalked after she had dumped her boyfriend a month ago.

Several users, who appeared to have known her personally, reacted with rage at the ongoing scourge of femicide, where women are killed by their partners.

Many changed their profile pictures with an anti-femicide campaign titled On Strike, End Violence Against Women to honour her.

Kgakgamotse Malepe posted: "For the next 7 days (sic) lets change our profile pictures to black in mourning of our beloved and a beautiful soul of Mosidi Sheila. RIP my sister, greet the angels for us."

Kgothi Mfulwane wrote: "An innocent soul taken by (sic) the name of love. To think that I predicted this really leaves me shattered. We really failed ever smiling Sidi."

Komani Kgonothi posted a message about the couple and said he envied their relationship.

"You guys where (sic) my 'IT couple'. I respected and cherished your relationship.

"I basically envied your relationship. I'm not going to judge but all I can say is that there was a better way to resolve your issues. Mosidi Sheila, my sister ... rest in peace."

The last time Kopanye's family saw the mother of two alive was on Friday morning when she left for work.

Kopanye's uncle, Mpho Molefe, told Sowetan yesterday that the family received a call from the police on Friday telling them Kopanye had been killed.

"We don't know what happened. All we know is that we have lost one of us. We are traumatised, shocked and this feels like a bad dream. It's like somebody would just wake us from this nightmare," he said.

Molefe said the family did not know the boyfriend.

He described his niece as a bubbly person, respectful and very popular.

"She was our everything. Family gatherings will never be the same; the chair that she sat on during gatherings and her children are a sad reminder of what we have lost," he said.

Molefe said the boyfriend was not the father of her two children, a boy aged seven and a girl aged five.

Temba police spokeswoman Sergeant Margaret Molane confirmed the incident but could not give details.

The boyfriend, according to Kopanye's family, has turned himself in at the local police station.

He cannot be named until he appears in court.