Here's kind of a wild idea.
What if Gwen is treated as kind of a high-mobility, low-health (5 HP) version of Rook, with the same emphasis on armored specials? For example…
B = armored version of Setsuki's slide
C = armored slow command throw that "steals" 1 HP
air B = something like Valerie's air B
air C = something like Setsuki's air C
And maybe some unique normals and supers.