Bam said:
Unfortunately I was person early in the game and had no idea you could get the augments from party members and stuff. Basically, I only have Counter, Auto-Potion, and Recall (what does that one do anyways?). Have I screwed myself over?
No, the game is quite beatable without the extra augments, but they do help.
Counter should go to Cecil and then you should immediately make it active. That will actually help you in this fight, since you can keep him on Defend mode and he'll retaliate against her physical attacks. Counter is great on Cecil no matter what, though, so it should definitely go to him.
The other two augments fail. What you use them for is fodder to gain other better augments. The way the augment system works is, you can obtain bonus augments from other party members after they leave, provided you gave them augments while they were in the party.
For example, after Palom and Porom leave, you can go to Mysidia and talk to the Elder in the tower, and he'll give you Twincast. But, if you gave Palom an augment, you'll also get Bluff. If you gave Porom an augment, you'll also get Cry. And if you gave 3 augments total to the twins, you'll get Dualcast.
At this point, the best places for those other two to go are to Yang. Once you complete the Sylph Cave sidequest later in the game, you'll get the augments for Focus, Kick, and Brace in return.
Bam said:
The problem with her is that she counters all of my attacks with Thundara/Blizzara/Fira and then immediately afterwards attacks again. I used a similar strategy to the one you just listed but I missed out on a few key things, so I'll try it again.
Which is why you restrict your direct attacks to Yang only

If you're attacking with everyone, you'll get demolished by the counter-attacks.
It should only take 6 Focused attacks at most from Yang to take her down. Just take it slow and keep healing.