What do you think that are the exactly age of: Neia, Brain, Calca, Remedios, Kelart, Gagaran, Tia, Tina, Tsuare, Zanac and Zesshi Zetsumei. In my case:

-Neia Baraja (15) 

His father mentioned that he would prefer that her daughter get married rather than her being a Paladin, so I supposed that she's already at an marriageable age or at least near.

-Brain Unglaus (27)

-Calca Bessarez (24)

Calca rised as the Holy Queen thanks  in part at her magic abilities as she was able to use fourth tier spells at the age of fifteen and has been mentioned that she has goberned for about ten years. So, supposing that she was crowned when she was fifteen, the youngest posible age, nowadays she would be around 24, if she is still alive -_-.

-Remedios Custodio (22)

I supposed that she's around the age of Calca and she's old enoguh for the nobles pester her about being unmarried.

-Kelart Custodio (21)

She's younger than Remedios and she is in her same situation.

-Gagaran (27)

She has been adventuring for a long time and she was already a veteran when she saved Lakyus some years ago.

-Tia & Tina (19)

I just feel that they are around the age of Lakyus. Maybe they are younger?

-Tsuare (21)

-Zanac (26)

-Zesshi Zetsumei (107)

Aura and Mare are 76 years old and look like children of 11, so I think that every seven humans years is equivalent at a year of growing for the elves. Since she looks as a teenager I think that her physical appearence is that of a girl of 14 or 15, so my guess is that number multiplied for 7, or so around.