Why has Emily never taken the métro?

(or any other chatacter atp) I just wonder because you could easily show another cultural difference. For example, a plot point could be that Emily would be overwhelmed of how to use public transit as she's not used to it from the US and then Gabriel could help her or smth like that idk xD It's just so weird to me how the métro is basically never shown even though it's such a huge part of Paris and pretty iconic!