The fact that the girl in the middle is a valkyrie, And one of the girls is a trained assassin, Along with a girl who has possession of a infinity stone, This is not a fair fight. If it was one on one, Then wonder woman, But their are three.
I would love to see Wonder Woman fight Black Widow, Scarlet Witch, And Valkyrie in a battle scene. Wonder Woman has skills and whips but Scarlet witch, I could see her using kinetic powers against her plus Black Widow did manage to beat up a dozen guys while tied up to a chair and Valkyrie, She's got her own way of fighting.
You would need Valkyrie, Scarlet witch, And captain marvel working together to even have a chance.
Wonder woman was shown to be faster than bullets and able to kill a Greek god of war that overpowered the gods.
Widow would be too slow and you need powerful people for powerful beings. It does not matter how many years of training and combat you studied if the other person is stronger and faster and competent at fighting.
Black Widow: her powers include high skills in hand-to-hand combat and expert tactician but all her 'powers' (like Captain America) are closer to peak-human rather than super-human. Her agility and strength are easily overpowered by Wonderwoman who is also trained in the art of war.
Valkyrie: As an Asgardian, Valkyrie has powers that would seem extraordinary compared to the average mortal or even Asgardian however it still pales in comparison to wonder woman. For instance, Brunnhilde is able to lift around double an average Asgardian can, 45 tons. Wonderowmans top lift has clocked around 500 tons. She has also been shown to be worthy of Mjolnir on multiple occasions but chooses not to use the weapon as it would not make a fair fight.
Scarlet witch: As Thanos approaches, Wanda destroys the Mind Stone with one hand while holding off Thanos, Who has almost a complete set of Infinity Stones, With her other hand. It’s truly impressive. Unfortunately, Wonderwoman bracers can be used as a defence against powerful magic created by Gods. Wonderwoman is also faster, Stronger and has greater powers of telepathy.