1. Beijing embassy replies:
The Danish consulate in Shanghai has the same rights as the embassy in regards to issuing visa and deciding on the visa validity. It is always possible for the applicant to apply for a longer validity but we are unable to advice if the request for longer validity will be granted before we begin the actual case processing as the decision is based on several factors.
2. Shanghai embassy replies:
Generally speaking, multiple entry visas are granted if the applicant can prove that he/she has had a reasonable number of entries in to Schengen within the last couple of years. In such a case we can consider a one-year multiple entry visa. A three year visa is however only granted rarely, and usually only if the applicant has previously held one or more 1-year multiple entry visas.
还有就是即使本来应该去上海递交的,因为目前看来北京申请多年多次往返的成功率比较高,可以去北京递签证。
Beijing embassy
You can hand in her application in Beijing if you lived in shanghai, but I cannot guarantee we will issue any different than Shanghai.