Yeah.....she's a descendant of Esper magic....on her Mum's side. I get the impression Strago is her maternal grandfather by blood, that its not some kind of Vivi/Quan adoptive grandpa thing.

She is naturally magical like Terra but....yeah....weird

The great thing ive found about this game is that you can tinker with that magic stat all you want....on most characters. I think in the end Terra's was the same if not higher than Relm's in my playthough.

Although....Im pretty sure Kanno said something about if you get that magic stat to 140 it resets to 0. I got nowhere near that...but that magic stat only has to be 50 to knock out 9999 with Ultima