Pho is my favorite! Your girlfriend might be better off bringing spices with her (I do this on each trip).
Isn't Pho a vietnamese dish? In my experience (in-laws)it's usually just meat and broth (beef or chicken) over rice noodles (these you can find here) and then jalapenos (sometimes available), siracha (available), bean sprouts (rarely available in my experience) and lime (readily available). She may also use the hot and sour mix, which I have seen in Belize City. Fish sauce I have never seen, but never seek it out either