What motivates the party? Saving someone's life or killing a goblin? Matthew's refinement is interesting as well - my only problem is that it forces one PC to make a decision for the rest of the party. That said, your decision to make it play out as a moral decision is interesting as well. How does the party handle this? Do they get defensive and yell back at her? Do they slump their shoulders and take it? Do they apologize and try to help her work through her grief? There's a lot of ways it can go. She's casting about for someone who she can point to being at fault for this, so she has to blame the next best thing - the party that was too late to save him. She's upset that her brother is dead, and can't blame the dead goblin. Grief is a powerful emotion, and people work through it differently than others. I kinda like the scene, mostly because it's a believable reaction from the woman.
While Burnt Offerings skews more to the former, this vignette skews to the latter.
Some groups want to always be Big Damn Heroes some have no problem with being villified by the people they protect like Spider-Man. If you don't think they'll take kindly to this particular story, then by all means, adjust it so that you can give them the best play experience possible. You know your players better than anyone else, Dan.
