What kind of soup is this lady most likely making?
There are actually two dishes being sold, and neither is "Phở". The words that she yelled and had Gordon do the same were "Hủ tiếu, Bún riêu". They are both noodle soups, the former is pork based broth, and the latter, porc and shrimp/crab with tomatoes. You can google the words for more info.