It is correct, sow-na might be hard because not sure do people know how to pronounce sow (female pig) correctly :). Other maybe better example is of “sour” without the r, and adding “na” on the end.

https://m.youtube.com/watch?v=IRtxq2qug7w

Finnish spelling is very consistent with its phonology. “a” and “u” are pronounced kind of similar to as they are in Italian or Spanish or something, except further back in the mouth. So yes