Weasley, I don't want to start a fight here over Violet Slughorn, but she's not just 'tolerant' of purism. All those conversations and her actions with Avery say she's a purist. If she's questioning it you need to have more tough love here. The thing is she had this DoM data for weeks and still went through with it, didn't she?
I don't think you should do that to help her. I think you should do that if you think it'll help the war position and any credence to what you've said before, and it might because of your placement in the Minister's Office. The thing is — you shouldn't associate with Slughorn. You'll probably hurt your own credibility if you're supporting someone who was going to marry a Death Eater.
Well I can help you with the transfiguration bit if you want. Albus also had some rarer books on the subject if you wanted some.