She's fine in your Bastilla Shan team for now.
DO NOT ZETA Bastilla. It's tempting, but save it. As soon as you have Jedi Knight Revan you'll reach a point where you rarely use Bastilla lead again. I'm not saying it's not a good zeta while you're using it, it's just that not long after you get it, you get a different leader and she won't get to use it anymore.
But Ahsoka will shine brightest in a Padme squad, or possibly a GK squad, depending on the use.
So if you really want to make Ahsoka all she can be, you'll have to farm separatists and unlock Padme, and then make sure you farm Jedi Knight Anakin, who gives her additional bonuses.
Farming Separatists can also be very helpful for your fleet. The geonosians under a Brood Alpha lead can 7* your Padme and serve as a solid GAC squad, while their ships form a formidable trio under Thrawn or Tarkin, and become dizzyingly wonderful on offense once you have the Malevolence.