It's not about the flight or s return ticket. The issue is a visa that will allow her to stay here. There seems no provision for her to stay based on your having a non B and work permit. It seems she would need a retirement visa which has specific conditions that she would have to meet. You are better to speak with immagration or Thai embassy in Colombia try a DTV she can enrol in a Thai cooking course
Anonymous participant 929 doesn't matter where the money comes from as long as you have it and not the date before you apply that's the issue people borrow from friends