That is sort of my point. She got hit by Doomsday, shrugged it off, smiled and jump right back in the melee. In the trailer she can't stop a bullet from killing/wounding her friend and needs the bracers to deflect bullets. Doomsday's punch > bullet.
Maybe she doesn't get it right away. During the trailer she seems to fly and get hit by lightning. Maybe a power up? If not, her power level fluctuates too much between BvS and WW. But this is just a trailer, so I agree it is early to say that with certainty.
Marvel Studios (those rasquels) have done good films with some rather bland superheroes. Mainly by dipping in genres other than action.