Is there any difference between joint preparation and separate preparation? I prefer to split some income to my wife manually so that I can get benefit from RRSP.

In my situation, I have 115,000 cad income in 2014 while my wife is 25000 cad. I contributed 20,000 cad to RRSP and my wife contributed 20000 cad to RRSP also. Can I use separate preparation and split some income to my wife so that it make my wife's RRSP MORE valuable for her refund?