The team at Kuzuko Lodge, a member of Legacy Hotels & Resorts, made the announcement on Thursday.
Angel and her cubs started moving around together on Monday. The cubs are about 12 weeks old and in good health.
The courtship happened during the first week of March this year, according to Kuzuko Lodge.
Sylvester made headlines after escaping twice and walking more than 370km outside Karoo National Park in 2016. He was finally caught after three weeks on the run when he was darted while asleep and eventually relocated.
The lodge said the animal’s future was uncertain but has been at Kuzuko for more than two years and settled into a tight-knit coalition with his male counterpart Fielies.
“Now, the proud father of two lion cubs, Sylvester and his lioness Angel, have shown us the true power of Mother Nature and defied all odds to become 100% integrated lions in the wild,” said the lodge.
General manager Gerhard de Lange said: “We have two lionesses in the reserve with whom the two male lions have established a close bond.
“Although both lionesses were on contraception we started to suspect that Angel had given birth between June 15-20 this year.
“Angel showed all the signs of having cubs suckling, but as lionesses keep their babies ‘hidden’ for quite a period while they are very young, we hadn’t been able to spot them.”
Angel is another Kuzuko success story as she was rescued as a 5-month-old, with her sister, as an orphan.
Instead of being tamed or raised in captivity, De Lange and his reserve team raised them to be 100% wild.
Sylvester was, during his “great escape”, almost euthanised because people simply didn’t understand that he was running for his life and needed a territory of his own and a coalition partner to join up with.
“Sylvester never fails to surprise me. Since I first heard of him through his jaunts through the Karoo - causing havoc during his time out of the protected wild - till today where he is completely integrated at Kuzuko, he is living proof that conservation, when done right, is always the preferred option,” said De Lange.