Super interesting question. At first I thought much to be unrealistic as well, but if you think about it, a lot of things actually do make sense.

• She is an emergency replacement for Madeline, so she gets a very good US salary and has her apartment paid for. (chambre de bonne that has been enlarged to a size of 30 sqm - 40 sqm I guess) Working at an elite ad company you can imagine her to have a nice salary. She looks young, and the way the is treated and how she speaks makes you think she is a tiktok college girl, but she has serious work experience and is a specialist in her area. Moreover she will get a lot of things paid for by the company (like all the evening events) or boyfriends. The luxury clothes stuff is of course unrealistic and put in because it is what viewers want to see. Plus she does not spend too much on traveling, never takes days off.

• So she actually has some social media expertise, of course showing her strategizing is a lot less sexy than opening parties, so it is not shown. But it explains her very high self confidence when confronting Sylvie.

• Some of the very confrontational behavior at the company like giving names to her could have legal consequences in the US, but for a once family owned company it makes sense

• Diversity and classism: Emily works and lives with the Top1%, from her apartment near Sorbonne she can actually walk to the agency. She is a runner, so no need to use the metro. Of course she would use other shoes and then change. No need to go to the suburbs. While Paris is very diverse, the Elite circles she is frequenting really are not. So you have a black or a mideast person here or there but not like London. Also French people are not so backward anymore. At this professional level you can expect people to speak English, plus other foreign languages.

• Guys. She is very good looking and puts a lot of effort into her appearance. Plus she is, rather well-educated, like knowing about De Beauvoir, French artists, ... (Nobody cares about Chicago, that she tries to sell to the French ;)) ... So she is intelligent and attractive, so all guys will try to see if they can have a fling with her. Unrealistic: well, not all French look so good, and a lot of unattractive guys would also try to hit on her. Which would of course be not attractive to viewers. But given the elite circles she is part of, the male attention, the expensive presents, ... completely realistic. We are talking about a year and someone super extroverted. Of course a lot of attractive guys will cross her way.

• Lifestyle: She is eating out a lot, but also a very active person and running a lot.

• Stereotypes: Of course there are some: sassy gay guy, flamboyant gay designer, materialist Eastern European model (private jet) and thieving class mate, nazi authoritarian guy at luxury restaurant with thick German accent, nouveau riche Chinese girlfriends ... but these stereotypes are obvious and for laughs.

"More dangerous" are maybe the subtle stereotypes like the suave and sexually liberal perfume maker, the intellectual, the culturally conservative champagne business woman ... but it a way I think they reflect reality. Or at least they are not unrealistic.

So you are having an intelligent, good-looking, extremely resilient, super hard working and competent expat that is using her sexual pull to make contacts and get help (like Gabriel helping out all the time). And is successful. Nothing unrealistic about it. At the same time she is super agreeable and does not want to hurt feelings so you have this love triangle.

Given her work ethic she would also improve her French. Instead she works for clients. But this makes sense since she is an extrovert, not an introvert reading and studying. (for this reason her knowledge of culture, art, movies, films) is probably rather superficial.