While it is unknown if Vitani ever saw Scar as a newborn, she seemed to be very supporting of Zira's plan to overthrow Simba. Did she have any sort of role in Zira's Pride? She certainly had a very mean-spirited
nature as a cub. She and Zira weren't really shown together from what we saw in SP. Its safe to assume she IS Zira's daughter with a rogue possibly, maybe even Scar himself. We unfortunately have no information about her parentage or her home-land, Zira was a very important figure in her life, she may or may not have took little Tani under her wing and raised her as her own.. maybe Zira was Vitani and Kovu's grandmother? They share a few similarities with each other. But they also carry many unique traits as well, such as Vitani's blue eyes and head-tuft. Kovu's dark fur and green eyes and also his strong build for an outsider who probably should've shown signs of starvation and also insanity.
Notice how Vitani's tail tuft is scruffy and unkempt, which is no surprise for being raised in a wasteland.
But Kovu shows no signs of any scruffiness or bad health. Which leads me to think that his true family lived in the Pride-lands. But Vitani seemed like a true warrior who was quite literally born in grief and raised in hate. But the twist at the end shows that even Vitani had a heart and sanity to stop the further spilling of blood and put an end to the division of the two Prides.
Vitani as an orphan with no parents is very likely because it'd explain how she would go against everything she was raised to believe in and even more for Zira to threaten to harm her own offspring.. but than again she was pretty 'coo coo' when Scar died and her exile.