I know it's been annoying seeing Becca cry constantly and seeing her character show very little development but let me just say I can see her looking up to Luffy after this finding a devil fruit of her own and down the road redeeming the HELL out of herself which would be great story telling. She is a product of her environment she has been treated worse than most of us could ever imagine but seeing Luffy actually take down her life's version of basically all that is evil may spark that hope in her and she can hopefully prove to be a great ally in the future.
–- Update From New Post Merge ---
Let's not forget she is with Luffy right now so if Doffy does stand up and make a speedy final charge at Luffy and Becca stabs Doffy in the face finishing the bastard it will feel so right.
I'm expecting Doffy to either stand up again/ get pounced on by Jesus and his fruit stolen/ or CP0 to come retrieve his body.