A copy certified by the Swedish Embassy is not considered adequate by the IRS ITIN Unit......
Alternatively she could mail to the IRS a complete copy of her passport certified by the Swedish passport issuing agency (if the Swedish passport issuing agency offers that service).
Isn't the Swedish passport issuing agency just any Swedish embassy or consulate ? An embassy or consulate always issues passports on behalf of governments, so what you say here is contradictory.
The W-7 form instructions say the following:
"You may be able to request a certified copy of documents at an embassy or consulate."
I did not know about Acceptance agents, but really all I need is for her passport to be certified so it is accepted by the IRS. I do not wish to file my tax return from abroad because I'm in the US now, my wife is currently residing in the UK until she gets her green card, which will be next year, so we are apart for the time being. If an acceptance agent is able to provide a certified copy only then I will look into it.
The reason she would use on the w-7 is e : Spouse of U.S. citizen/resident alien
She will probably obtain a SSN in 2016 when she arrives to the US, but in 2015 she is only eligible for an ITIN which I wish her to have so I can get an exemption.