The leggy blonde model tweeted that Valentine's Day should be "a day of love for everyone."
Instead Reeva Steenkamp was shot dead in the home of her boyfriend, paralympian superstar Oscar Pistorius, who was charged with her murder.
Steenkamp, South African model with a law degree, campaigned against rape and violence against women. Thursday morning, Reeva Steenkamp was to give an inspirational talk at a Johannesburg school. The next day she was going to wear black to protest the brutal rape and mutilation of a 17-year-old.
But the glamorous South African celebrity was found dead in the early hours from four bullet wounds in the Pretoria home of Pistorius. The two had been dating for only a few months.
She was one of FHM magazine's 100 Sexiest Women in the World for the past two years, appeared in international and South African advertisements and was to make her debut next week as a celebrity contestant on the reality TV show "Tropika Island of Treasure" filmed in Jamaica. She was also the South African face of Avon cosmetics. Police said the model was 30.
The freckled blonde who appeared in scanty bikinis on magazine covers and sashayed down fashion ramps was "continuously breaking the model stereotype," said her publicist Sarit Tomlinson.
Steenkamp was "the sweetest, kindest, just angelic soul" and at the same time "a very inspiring individual, very passionate about speaking about women and empowerment."
Scores of tributes were posted online. Fellow model Mashadi Motsogi tweeted: "You will be missed my sister. I can't hold the tears back. Love you always. RIP."
Thursday morning, Steenkamp had been scheduled to give a motivational speech to school students in Johannesburg. "It was about empowerment and inspiration and what inspires you and how to follow your dreams," said Tomlinson, who had Steenkamp's notes for the speech.
Steenkamp was born in Cape Town then moved with her family as a child to Port Elizabeth. There she attended the Nelson Mandela Metropolitan University, graduating with a Bachelor of Law degree.
"She had a fantastic character and we all were very fond of her," said Hilda Fisher, secretary to the dean of law.
Six years ago, Steenkamp moved to Johannesburg, South Africa's commercial capital, after she won the contract to represent Avon.
On Twitter, Steenkamp tweeted messages urging women to stand up against rape as well as her excitement about Valentine's Day.
"What do you have up your sleeve for your love tomorrow?" she tweeted. "It should be a day of love for everyone."
Her last tweet was an enthusiastic acceptance of a friend's invite to celebrate the day with chocolate cupcakes topped with red hearts.
She also used her Twitter account to encourage her thousands of followers to fight sexual abuse.
"WEAR BLACK THIS FRIDAY IN SUPPORT AGAINST (hash)RAPE," she re-tweeted just hours before she was killed.
Steenkamp urged followers to stand up against violence against women, tweeting four days ago as South Africa was outraged by the particularly brutal rape and murder of a 17-year-old: "I woke up in a happy safe home this morning. Not everyone did. Speak out against the rape of individuals in SA (South Africa). RIP Anene Booysen (hash)rape (hash)crime (hash)sayNO."