I agree with 'the world is saved' -- These two cards share a lot in common. Because one is major arcana and one minor, I'd say the Empress in the relationship is thinking long-term / big-picture while the 9 of Pents is having a hard time moving past the day-to-day.
In my own readings, I tend to look at the 9 of Pents as a person accomplished in her field, independent, and at the cusp of deciding whether or not she wants to share that wealth (by "making" the family depicted in the 10 of Pents). The Empress is all about creation / sharing that wealth, so yeah, there's a basic tension here. I would say that those trust issues you mentioned need to be addressed in order for them to move forward into a fruitful relationship.