Say it isn't so! This drop-dead gorgeous name is so rare it was only given to 6 girls in 1998, and that's it. And yes, she's legit. As is the case with Katherine/Catherine, Katriana is another option, both a variant spelling of Catriona. Catriona is the Irish and Scottish way to spell Catrina, from Katherine, meaning "pure." Catriona is pronounced kuh-TREE-nah. Caitria is another version of the name used in Ireland.
Catriana can be found at least once in a published work - The Celtic Monthly.
What isn't so clear is the intended pronunciation of Catriana. Did someone see Catriona in Ireland and mistake the pronunciation for kah-tree-ON-uh, then take the name elsewhere as Catriana (kah-tree-AH-nah)? Is it just a case of name typo? Or down another path, did someone first intend it as a different spelling for Catrina, independently of Catriona? Similar events led to the family of Caterina/Catarina, Catherina/Catharina, Cathryn/Kathryn etc. If you take a look at the multitude of names related to Katherine, especially the Sardinian version Caderina, it's a wonder Catriana hasn't been noticed by anyone. The absence of clarity on this name's spelling origin, undoubtedly because it is so rare, is actually a bonus. You can choose how you want to pronounce it.