No, she couldn’t
It was unfortunate that poor Morgan Stark had to sit idly by, wondering why her father wasn’t going to make it home. And to make things even worse (if that’s at all possible), he totally would’ve come home had Scarlet Witch intervened. At least, that’s according to a tweet by Kevin Feige, the president of Marvel Studios.
He said that Scarlet Witch possessed the power to take Thanos on all by her lonesome, something that fans were quick to call nonsense on. Seriously, take Thanos, the strongest supervillain in the MCU all by herself? Well, thanks for not stepping in, Witch. Half the universe is dead because of your negligence.