In case you haven't noticed (but I'm pretty sure you have already), most Suikoden heroes don't wield bladed weapons or at least aren't swordsmen. Only Lazlo can be a considered as the swordsman among the heroes, and he uses a dual-wield style at that. Hugo does wield a bladed weapon, but it's more of a melee-type dagger than a sword.
If we model an adult female Tenkai after Kika or Chris, I don't see any reason why would a Tenkai not wield a sword. For a younger Tenkai like the usual, though, the reason why I like Suikoden so much is that it doesn't use too many RPG stereotypes and yet is just as popular (if not more popular) as the likes of Final Fantasy. And so I don't see a problem with non-swordsman Tenkais as well.
That said, in keeping the Suikoden tradition of mage knight heroes (all of them (except Kyril, if you even consider him as one) actually, but Riou and Frey stand out as healer types; I can count with my fingers how many games have a healer protagonist, maybe Terra and Yuna from FFVI and FFX respectively), of course the featured True Rune shall be spell-type, though we have yet to see a passive-type TR like the Sovereign Rune (semi-active, as it also transforms the wielder into a Golden Hydra at the cost of the rune's Anti-Magic property).
So, for a female Tenkai, which TR type would you prefer: offensive (Soul Eater, True Fire, Punishment), healing (Bright Shield, Dawn), or passive (Sovereign)?
It's not all about knowledge, but it helps.