Here's my fanwank. Maybe Philip met her as Scott Peterson in some other capacity--say, he was working somebody else and met her at a party of something--and then realized what a good asset she would make because of her husband and her personality, so then adjusted "Scott's" backstory to give him some ties to Sweden. Because she herself is supposed to have some ties to the country, but I don't think she's supposed to actually be from there. That in itself was a common thing, I think, to pretend to be from a country the person felt positively about.

Because it's just so weird and blatant that they haven't tried in the least to actually pass off this character as Swedish.