Since the OP hasn't been updated in a long time, I wanted to just post Batgirl's most important combos here. You can play Batgirl pretty close to optimally using only these combos and variations thereof:
Ground String = Any cancelable string that leaves them grounded
Juggle String = 212, F212, 23, F23 (212 may not apply in corner)
Midscreen
B12, B2U3, D2 xx Bola, J2, 111 - 26% vortex
B12, B2U3, D2 xx Bola, J2, F212 xx Flying Bat[MB], 12B2 - 31% corner carry, hard knockdown
B2U3, B2U3, D2 xx Bola, J2, 111 - 28% vortex
B2U3, dash, F23 xx Flying Bat[MB], D2 xx Bola, J2, 111 - 35% metered vortex, switch sides
B2U3, B2U3, D2 xx Bola, J2, F212 xx Flying Bat[MB], 12B2 - 33% corner carry, hard knockdown
Ground String xx Redemption[MB], B3, J3, D2 xx Bola, J2, 111 - ~35% vortex
Juggle String xx Flying Bat[MB], D2 xx Bola, J2, 111 - ~28% vortex
F212 xx Redemption[MB], B3, Bola, J2, 111 - ~30% vortex
D2, J2, Smoke Bomb[MB], dash, B3, Bola, J2, 111 - 21% vortex
B3, J3, B2U3, D2 xx Bola, J2, 111 - 35% vortex
F3, B2u3, D2 xx Bola, J2, 111 - 28% vortex
F3, F23 xx Flying Bat[MB], D2 xx Bola, J2, 111 - 35% metered vortex
Flying Bat[MB], B2U3, D2 xx Bola, J2, 111 - 28% vortex
Smoke Bomb[MB], dash, B3, J3, D2 xx Bola, J2, 111 - 24% vortex
Bola[MB], B3, J2, 12B2 - 27% hard knockdown
Bola[MB], B3, J3, F21 xx Batwheel(U) - 32% damage
Corner
B12, F23, D2 xx Bola, walk forward, NJ2, 111 - 29% vortex
B12, F23 xx Flying Bat[MB], D2 xx Bola, NJ2, 111 - 34% metered vortex
B2U3, B2U3, B2U3, D2 xx Bola, walk forward, NJ2, 111 - 33% vortex
(B12/B2U3), F23, F23, 111, F212 xx Batwheel(U) - ~45% damage
(B12/B2U3), F23, F23, F23 xx Flying Bat[MB], F23 xx Batwheel(U) - ~54% metered damage
Ground String xx Batwheel(U), F21, D2 xx Bola, walk forward, NJ2, 111 - ~36% vortex
Ground String xx Batwheel(U), F23 xx Flying Bat[MB], D2 xx Bola, NJ2, 111 - ~44% metered vortex
Ground String xx Batwheel(U), F23, 111, F212 xx Batwheel(U) - ~47% damage
Ground String xx Batwheel(U), F23, F23 xx Flying Bat[MB], F23 xx Batwheel - ~56% metered damage
Juggle String, F21, D2 xx Bola, walk forward, NJ2, 111 - ~30% vortex
Juggle String, F23 xx Flying Bat[MB], D2 xx Bola, NJ2, 111 - 40% metered vortex
Juggle String, F23, 111, F212 xx Batwheel(U) - 37-44% damage
Juggle String, F23, F23 xx Flying Bat[MB], F23 xx Batwheel(U) - 47-55% metered damage
212 xx Batwheel(U), F21 xx Batwheel(U) - 34% damage
(D2/F3), F23, F23, 111, F212 xx Batwheel(U) - 34/44% damage
(D2/F3), F23, F23, F23 xx Flying Bat[MB], F23 xx Batwheel(U) - 41/52% metered damage
F3, F23, D2 xx Bola, walk forward, NJ2, 111 - 31% vortex
F2, F23 xx Flying Bat[MB], D2 xx Bola, NJ2, 111 - 35% metered vortex
Bola[MB], J3, F23, F21, 111, F212 xx Batwheel(U) - 42% damage