Here's how I did this. In a browser log in to Google > mail > Calendar. Go to the"my Calerdars" area, hit the arrow by her name and select "Share This Calendar", and enter your Google acct. info. Next log on to your wife's Google calendar and do the same. Now, in each calendar make sure both your and and your wife's account are checked to display. Now on your phone (not sure how BB syncs) you can choose which calendars you want to sync.

Hope that was clear...