I got Morgan (F) but her ivs are +spd -atk

happened to me too
-Atk +Spd curse :/
You could try going full on tank with Res refined blarserpent.
Mirror strike too.
B skill could be a breaker or qr
C flexible
distant Def seal.
Her Res will go pretty much through the roof in enemy phase.
Oh, and she'll be depending on Glacies.

Bummer my dude
Would you run her on a flier team?
If so I say she's worthy especially if you go blarblade plus hone fortify support.
My Morgan feels a bit slow so I've put everything into attack hoping to one shot, hope this helps!