Upvote:4
I have traveled multiple times on Schengen visa so I speak from experience. I confess I have sometimes obtained visas from one country and never even visited that particular country. It's still unethical anyway.
Answers to your questions:
She did not declare the Sweden and France trip in the visa application, will that be okay?
At the time she applied for the visa, it was unethical not to reveal the Sweden and France trip however that is already done. If you are asking if it is okay in case it is found out, I will say it depends on which immigration officer apprehends her. As it stands with her new plans, the purpose of her visit has completely changed and an immigration officer is within his reasonable rights to refuse her entry IF he finds out.
Will the immigration officers find out that she changed her purpose as a tourist? (even if she shows proof of accommodation as a tourist, letter of invitation from her family in Sweden, and plane tickets following the new plan?)
It is unlikely unless it is annotated on the visa or she tells him. Of course he CAN find out easily if he is so suspicious he decides to check with the issuing embassy. The chances he will check are slim, unless something serious spooks him about the lady.
Will she be allowed to go to Sweden first and stay there for a week before spending more days in Norway?
Once again it depends if they find out. It is acceptable to spend time in a different country from the one of your main event. If there is an annotation on her visa showing the dates and reason for which she applied, she can be denied entry at the border. Of course some lenient officer might let her through.
Does she really have to spend more days in Norway because the Norwegian embassy issued it?
Technically YES she is supposed to, however nobody will be checking unless she tells them herself
How will authorities know how many days you spent per Schengen country if there are no border control within the Schengen area?
They will NOT, unless she tells them.