Can't see her winning, since Thanos is resistant to Telepathy far beyond hers, and he's durable enough to resist reality warping, which also makes her transmutation powers ineffective.
If the CU power actually boosted Sersi's abilities the way it boosts regular humans Thanos could be going down, or at the very least he won't win this. An ordinary human CU beat down and mentally messed up Juggernaut seemingly easily. I'm not sure Thanos would be resisting a boosted-Sersi level of transmutation power directed by an expert at transmutation.