Seniors and students

She would qualify for the tuition credit for 2009-2011 if she was considered a resident of Canada during that period. Then the amounts would be carried forward if she didn't use them on her tax returns for those years. 

But, to apply for the tuition credit for the years 2009-2011, you would need to file tax returns for those years, and typically the CRA doesn't accept returns from more than 10 years ago. You can contact the Canada Revenue Agency (CRA) and see if they will still allow those returns.

If you are in Canada or the United States, you can call the CRA at 1-800-959-8281. If you are elsewhere, you can call 613-940-8495. This page has more ways to contact the CRA: Contact the Canada Revenue Agency

As for where to get the slips, the universities should have an Alumni association that can at least point your fiancé in the right direction. Other slips like T4s for work or T4As scholarships, bursaries, grants, etc... might be harder to get.