First things first, Tifa and Aerith. Interestingly, both of their first names are derived from the same origin: the Tiferet, a particular sefira, or branch, of the Sefirot in the Kabbalah. Now, I'm not gonna get into the discussion about whether or not that makes Aerith or Tifa Jewish, since it's just their first names and they clearly don't think they're Jesus.
Since Tifa, like Cloud, comes from Nibelheim, that would make her Danish too, wouldn't it? Though her last name, Lockhart, is actually of Scottish/German origin, from the words "lock" and "hart", meaning "hardy".
Now, I don't remember where it was that I heard that Nomura apparently said he designed Aerith as distinctly more "Western" and Tifa more "Eastern" to show their dichotomy, but I do remember there was that whole "fiasco" in 2019 from the JP fandom that complained about Aerith's face and thus she was redesigned to be "cuter" for the final game. (
Tokyosaurus has a good video covering it.)
But at the same time, nowhere in any official source like the Ultimania or any interviews that I can find can confirm if Tifa is meant to be specifically "Asian". She certainly has some genetic traits that match East Asians, but then again, straight black hair and deep reddish-brown eyes aren't exclusively Asian traits. (And as far as I can tell, neither she nor Aerith have the distinctive "Asian fold" at the front of their eyes that is partly responsible for why some East Asians seem to have smaller-looking eyes.) There are plenty of people of the Mediterranean who are Caucasian, but also have such traits, and they aren't necessarily mixed-race or descended from Asians. Granted, there is quite a bit of cross-culture finagling going on there thanks to their proximity to the Middle East, which has been a thing since ancient history and partly why many European languages have origins in Proto-Indo-European.
But ya know what, if people wanna headcanon Tifa as having Japanese ancestry or something, go for it. She at least looks the part.