No, she couldn't
Unfortunately, poor Morgan Stark had to sit idly by, wondering why her father wouldn't make it home. And to make things worse (if that's at all possible), he 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. 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.
