Hello Chatwant
According to the Operational Manual for Overseas Processing 2, section 10.3: (http://www.cic.gc.ca/english/resources/manuals/op/op02-eng.pdf) “Sponsors of dependent children and of spouses, common-law partners or conjugal Partners (unless they have dependent children who have dependent children of their own) do not have to meet financial requirements, but they do undertake to provide for the basic necessities of the sponsored applicants so that the applicants do not need social assistance.”
Therefore, she does not have to prove that she earned the minimum necessary income in order to sponsor you, but she should not be on any social assistance or welfare. In the application there is a section that asks something like "if sponsor is not living in Canada, provide proof that (s)he will be returning to Canada after the approval." If seems that your ADR is for the same purpose.
Send them more evidence than they asked for showing that she is there and planning to stay there.
BTW if you need a link to OP1 it is http://www.cic.gc.ca/english/resources/manuals/op/op01-eng.pdf
Also see http://laws-lois.justice.gc.ca/eng/regulations/sor-2002-227/page-55.html section 130 for sponsor's approval.