So how, then, does she fight the boar?

She does not. She dispatches it. 

Were you expecting a tale of strength and heroism and red in tooth and claw struggle? Fool, you have learned nothing from this tale. If you wanted to know that Robena was strong you could have observed that in her size and muscles from the first page of this story. 

So perhaps your problem, then, is the same as hers. You hunger for the blood and the sweat and the push and pull of spear and flesh. You hunger for the clatter of dice, in which case you will be satisfied to hear of her twelve. Do you recall the blow she landed on King Pellinore's kneeling neck? Do you recall its strength and skill? Do you celebrate it? Would you say that, but for the moral technicalities surrounding it, that is a tale worthy of telling about a knight?

You ask her, this girl who has spent this last year struggling with death, atonement, and knighthood how she kills a pig? Shame on you. Shame on those like you. Shame on her for being like you. Shame on her no longer.

This is not her final trial. She will not make the mistake of considering it so.