Number Thirteen won't be able to make it for now, so the most suitable person Gao Yang can think of is Eileen.
Eileen is good at fighting, adept at dealing with close-range emergencies, speaks multiple languages, and importantly, she is a woman. Women tend to be perceived as less of a threat no matter what.
What Gao Yang considered was the situation of doing business in Ukraine in the future, but the salesperson must have misunderstood, as Yelena was with Gao Yang.
The salesperson pointed at Yelena and chuckled: "Does this young lady need it? Our company does not have fashionable bulletproof dresses for women, however, women's suits or professional attire are no problem."