Africa is large, communications are poor, and I'm guessing. But this makes sense to me:
The African language everyone has heard of is Swahili, the main language of Kenya and neighbouring parts of East and Central Africa. Most people there speak a bit of it, just to get around. Now, most African languages differ from Western ones in that they use prefixes where we might use a suffix or do things another way - we add things on to the ends of words, like lion + ess = lioness. They would be more likely to have a form like: *esslion. See what I mean?
Now, the word Swahili is the root word. When you mean the Swahili people, it would be the Waswahili (I think ...). And when you mean the Swahili language, the correct form is Kiswahili. So you can see that Ki- can indicate "language", if you join it on to the word for the people who speak that language.
Swana is the problem! Down in Southern Africa there is a country called Botswana, where Bo- indicates the place where the Tswana people live. They actually speak a language called Setswana, but I could easily imagine someone taking the Ki- from Kiswahili and adding it to, not the correct Tswana form, but Swana, which would be an easy mistake - either that, or they just might have thought it sounded nicer, or easier for English people.
When tribal people name themselves, they usually go for a name that means The People, or The Free People. So Kiswana could be A Free Girl Who Likes Talking ...
As I say, it's a guess. It's also a minefield, choosing a name that might mean practically anything. I hope your daughter enjoys hers.