She got the PR and just landed recently. She gave my address for the PR card. Our address.
So there is no has to return every 6 month rule?
Never heard of a '6 month rule'.
OK, so you are saying she landed recently using her CoPR and gave your address in Canada as where they should send the PR Card. She can certainly leave Canada at any time. However, she will not be able to board a plane coming back to Canada (the airline won't let her) until she either has the PR Card in her hands, OR unless or until she obtains a PRTD (Permanent Residents Travel Document - a 'one-off' piece of paper that can be obtained though the local Canadian Visa Office, but it is a fair old form with lots of attachments and may take a few days or weeks to be processed). The only way 'around' this might be for her to fly to the USA and for you to pick her up by private car and drive back through the border - in which case, her stamped copy of the CoPR would work).
The PR Card 'should' come through in about 2.5 months (current times quoted as 61 calendar days, allow a few days either end of that for post). For current processing timescales, see here:
http://www.cic.gc.ca/EnGLIsh/information/times/index.asp You should then courier it over to her (I did this for my wife's card). I would use a 'proper' courier firm (i.e. NOT Canada Post).
Once she has her PR Card, she can return on the next flight if she wants.