I don't think 45 would be in Slytherin. Leaving aside the "They're the bad guys" simplification, Slytherin is all about personal ambition, and 45 doesn't really go for that.
Her EW core and contingency planning might put her in Ravenclaw, but I'd say her absolute dedication to her own people, even before her own life, would place her in Gryffindor.
