[@Jaredthefox92], for the first point, I'd like to indicate that there have been snipers of varying ranks at varying ages. An example of this is the Soviet sniper Roza Shanina, who died at the age of twenty and at the rank of Senior Sergeant. Another example of a low age gaining a higher rank than their age would have is Zliya Nurmuhametqyzy Moldagulova. Though Corporal isn't exactly a high rank, she did obtain it at the age of eighteen, and there are reports of snipers having joined the war effort at the age of seventeen. I'd also like to point out that Corporal is an JNCO rank within the Soviet Army, so that adds evidence toward the fact that a higher NCO rank would not be far out of reach for someone so young. A different example is also Noah Petrovich Adamia, who died at rank 24 at the rank of Starshina, which is the equivalent to a Company Sergeant Major.

In terms of my character, it is simply that she entered the Soviet Army and Sniper Corp at the age of seventeen, as some did. It would give her four years of experience, which although isn't enough was enough to give Roza Shanina the rank of Senior Sergeant. If you're still not happy with what I've just evidenced, I can bump her age up a bit if you want, or just lower her rank a bit.

As for her birthplace, it is, well, her birthplace. I apologise for my joking tone here, but I'd be surprised if she [i]wasn't[/i] born there prior to the war, else she would have entered the Army at the age of between one and five. To just cut things off, it's her birthplace, not her permanent place of settlement. In reality, she moved a lot, and most of her time was spent running away into the land regardless, to hunt or otherwise.