Also, try modding for damage and/or crit damage instead of crit chance.
And like others are saying ... save her for last. Daze her (or shock her), then burn down a different toon. She won't cleanse herself cause she'll have the highest health. Disabling toons are the most useful (daze, stun, shock, heal immunity, tm reduction).
I went up against a zariss, gk, zqgj, zoda, and ani team in my GW node 12 yesterday ... amazingly I beat it, eventually, but I actually killed QGJ first, then yoda before going after bariss. Most of my teams are crit heavy too (droids, rebels, boba), but I mod for crit damage so I get the burst that can carry me through her heal. GK's crit immunity also worked against his team some ... but it also worked for them. That battle was actually the most fun I've had in this game in a while ...