I think you'll get into most (if not all) of the programs you apply to as you've got work experience and your gpa and GRE scores are overall quite excellent! The average quantitative score for even the Emory MSPH program is 159, the GLEPI says 1/4 of admitted students have a 155 or lower, anyway, admissions are very hollistic, and a lot of people, maybe half of admitted students to all the MPH programs at Emory don't even have work experience, so you're fine. Obviously a fourth of the GLEPI is making it to graduation at Emory, so if you want Epi go for it!
Definitely leave in any and all top programs you want to apply for, realize that you are competitive and don't go to second tier programs like BU, GW, OHSU/PSU or others without a good sized merit scholarship I would say. You have a really good work experience and Poli Sci/French background, adding a hard skill like Epi to your toolbox would be great to improve your breadth of competency/understanding in public health.
Personally, if I was you I'd add MPH Epi programs at Harvard, UNC and JHU and just wait and see what happens, at those programs along you'd probably get into 2 or all of them anyway. Go to a top tier school for Epi as you'll be with other students who have slight more experience with math-related work and you can learn from them too, at many schools your Quant would be above average for admitted students despite you being concerned about it.
Thank you for taking the time to respond. I think I just saw some schools' epi websites and stats and freaked myself out, but your response is really supportive and definitely makes me feel more confident in what I'm doing! (And I didn't know about that Emory GLEPI stat). Thanks again and good luck with your apps!