Well, since your character is a mercenary - which I assume means she's working for money - you might want to think more about the shape of the different economies? In the most practical terms, do they get paid in coin or in kind? Will coins in any one place be valid in any other place, and might this serve to hold them in one country? ("We'll be shot if they catch us using *these* coins in their markets!")
Also, on the topic of food and diet, might there be taboos? I imagine that someone from a plains society might have a reverence for horses, and when she sees horses bred for slaughter in stalls - that will be a problem for her...