+Def F! Morgan

Yeah, she'll be fairly good against archers with her good atk, and Triangle adept and distant defense will take care of her shaky defenses. OR you could give her the Iote's Shield seal to make her a dedicated Archer killer, it's rly up to you

She really doesnt have the defenses to be a raventome, I'd really advise you not to do that. Especially since she's a flying unit. Spring camilla is an exception in that regard, since she does have 30 base def and can reach defenses high enough where bowunits wont be able to touch her, thanks to raventome and triangle adept.

You should really check her bane. Depending on that you could go different routes and if you are looking into making a defensive build -hp or -spd would be the better bane in that case.
Either way tho, she can still be a decent res tank with her natural A slot and tome, adding distant def seal to her would benefit her even more. But you cant expect her to tank bows with that def, even with a +def, Iotes shield + distant def combo.