Actually, I think Kath and I discussed whether or not Miss Wisconsin USA is a DG and we don't think she is. There isn't a DG chapter at Marquette. There's a possibility that she transferred from another school to Marquette, but since she doesn't list another school under the "education" section of her resume, it's more likely that she just helped out with the DG philanthropy.
I had a list of all the Miss USA Greeks but unfortunately it's on my computer at the sorority house and not here (at my parents' house).
As for Tri Delts, I believe Miss Kansas USA and Miss North Carolina USA are both Tri Delts, and although I couldn't find anything to completely confirm it, I'm almost positive Miss Alabama is as well.