My comment was a respons to: "Perhaps that's the reason why the Riksdag wants out in granting final consent to royal marriages - if something horrible and damaging to Sweden comes out on the consort it approved it would hurt that representative's political career? Questions raised on the approval process and how thorough was the vetting?"
Yes. The kings children need the formal approval of the parliament to be allowed to marry into the family. That's correct. To the best of my knowledge, this is also just an old symbolic tradition - just like the inspection of newborn royal babies. No one seriously thinks that a royal child these days would be switched at birth (or something like that). It's just a tradition. The same goes for the formal approval of a royal marriage. I have no doubt that all the partners of the royal children are thoroughly screened from a security point as soon as they start dating - it would be irresponsible to let a security risk have access to the royal family. But there is no "vetting process", if you mean that the prime minister and his cabinet sit down to have discussions about if Daniel, Sofia and Chris are suitable to marry their (now) spouses.