I don't think this is really a hint at a new combat job at all. It clearly puts what she wants to do (travel the world providing medicine) in direct contrast with what the boys want to do (learn to fight), including your own participation in the form of gathering grapes vs. actually fighting monsters. Additionally, the Japanese name for the "Chemist" job has always been the exact same as the Alchemist crafting class which is already in the game; it was also the same in FFXI as a crafting skill.

This doesn't mean they couldn't add it, and personally Chemist is my top pick for the next healer and has been since before Astrologian. I just don't see this as much of a "hint" at a new job at all.

Now if Alphinaud starts throwing around potions in 5.5...that could be the time to get excited.