Is there a hint of a future job according to this character (spoilers)?

[Penthea]

The guest character designer didn't know that 14 doesn't have a hammer-wielding combat job. It was basically an accident.

Mind you, I'd love a hammer job, but Gaia's not really an indication of anything to come.

This is exactly what happened. Tetsuya Nomura was asked to design Gaia and he wasn't aware that no classes use a hammer in combat. When Yoshida saw the art he was like "oh no one uses this weapon, but we can make it work."

I don't think she is a hint of a new class. She could definitely be made into one, but I think it's also just as likely that Gaia will have a unique combat style due to her very unique abilities as an Oracle.

I would love to see a class that uses giant hammers. Looks awesome.