Thai g/f Visitors Visa for Canada advice

My Thai g/f wants to come to visit me in Canada for 3 weeks. We have a relationship over the past five years. We live together when I am in Thailand 7 months of the year and maintain a condo while I am in Canada for the other 5 months (for health insurance qualification reasons). She has a masters degree, works at her job at an International company for seven years, makes about 60 kBaht/month, has about 250 kBaht in long-term savings, has a letter from her company stating her employment record and granting her 3 weeks vacation for the stated purpose of travel to Canada. She has a title to some small land and no children. So I have two questions:

1. Can anyone tell me what her odds of approval are, based on personal experience/knowledge of Canadian tourist visas?

2. Should we be minimizing the details of our long-term relationship or emphasizing this? One thought I have is that if I explain the relationship and invite her by letter to visit my country and meet my family it might help the cause but someone suggested this would be a negative as they might believe it strengthens her potential ties to Canada and she may not return to Thailand after the three weeks. On the other hand, if I am portrayed as just a friend, they might think it unusual she would want to travel so far for a vacation.

What do you all think is the best approach?