This is an answer that a Ukrainian friend of mine came up with for Australia; it applies just fine to this scenario too.
Actually, what the hell: I’ll link to her since she has a Wikipedia entry: Maria Tumarkin.
No, Maria’s Ukrainian Jewish ancestors were not directly involved in the genociding, literal and cultural, of Australian Aboriginals. Just like my Greek Orthodox ancestors weren’t.
But she, and I, are beneficiaries of it. And we should acknowledge it.
And (to add my own 0.02 AUD): guilt is not the point. The point is not to contribute to making it even worse.